diff --git a/.vscode/launch.json b/.vscode/launch.json
new file mode 100644
index 00000000..d6e74d64
--- /dev/null
+++ b/.vscode/launch.json
@@ -0,0 +1,14 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "type": "node",
+            "request": "launch",
+            "name": "Launch Program",
+            "program": "${workspaceFolder}/backend/app.js"
+        }
+    ]
+}
\ No newline at end of file
diff --git a/backend/app.js b/backend/app.js
index 76439f06..4935d25a 100644
--- a/backend/app.js
+++ b/backend/app.js
@@ -88,7 +88,7 @@ function storeToken(token) {
   try {
     fs.mkdirSync(TOKEN_DIR);
   } catch (err) {
-    if (err.code != 'EEXIST') {
+    if (err.code !== 'EEXIST') {
       throw err;
     }
   }
@@ -109,11 +109,15 @@ function getPairs(callback){
      if(err) {
        // Handle error
        console.log(err);
-       return null;
+       callback(null, true);
      } else {
        const pairs = [];
        
-       lastRow = result.valueRanges[0].values.length;
+       try{
+        lastRow = result.valueRanges[0].values.length;
+       }catch(err){
+         lastRow = 0;
+       }
 
        for (let i=0;i<lastRow;i++){
          let name1 = result.valueRanges[0].values[i][0];
@@ -122,7 +126,7 @@ function getPairs(callback){
           pairs.push({name1:name1,name2:name2});
          }
        }
-       callback(pairs);
+       callback(pairs,false);
      }
     });
 }
@@ -139,74 +143,171 @@ function getAvailableNames(callback){
    if(err) {
      // Handle error
      console.log(err);
-     return null;
+     callback(null, true);
    } else {
      const names = [];
      
      for (let i=0;i<result.valueRanges[0].values.length;i++){
-       let name = result.valueRanges[0].values[i][0];
-       let available = result.valueRanges[1].values[i][0];
        
-       if (name && (available=='x')){
-         names.push(name);
-       }
+      try{
+        let name = result.valueRanges[0].values[i][0];
+        let available = result.valueRanges[1].values[i][0];
+        if (name && (available==='x')){
+          names.push(name);
+        }
+      }catch(err){
+      }
+      
      }
-     callback(names);
+     callback(names,false);
    }
   });
 }
 
-function MakePairs(callback){
-  executeAPI(getAvailableNames,function(names){
-    executeAPI(getPairs, function(pairs){
-      let next_i=false;
-      const newPairs = [];
-      const usedNames = [];
+var matrix = [];
+var tree = [];
+let done = false;
+
+function count_pairs(row, col, cntr){
+  if (done) return;
+
+  matrix[row][col] = 2;
+
+  //mark all fields in matrix related to row and col names
+  for(let i=0;i<row;i++) matrix[row][i] = (matrix[row][i]===0)? cntr: matrix[row][i];
+  for(let i=0;i<col;i++) matrix[col][i] = (matrix[col][i]===0)? cntr: matrix[col][i];
+
+  for(let i=row;i<matrix.length;i++) matrix[i][row] = (matrix[i][row]===0)? cntr: matrix[i][row];
+  for(let i=col;i<matrix.length;i++) matrix[i][col] = (matrix[i][col]===0)? cntr: matrix[i][col];
+
+  //find next pair
+
+  let found = false;
+  for (let i=0;i<matrix.length;i++){
+    for (let j=0;j<=i;j++){
+      if (matrix[i][j]===0){
+        count_pairs(i,j,cntr+1);
+        found=true;
+      }
+    }
+  }
+
+  if (!found){
+    let inner_tree = [];
+    for (let i=0;i<matrix.length;i++){
+      for (let j=0;j<=i;j++){
+        if (matrix[i][j]===2){
+          inner_tree.push({row: i, col:j});
+        }
+      }
+    }
+    if (inner_tree.length === max_pairs) {
+      done=true;
+      tree.push(inner_tree);
+    }
+  }
+
+  //remove marks from matrix 
+  for(let i=0;i<row;i++) matrix[row][i] = (matrix[row][i]===cntr)? 0: matrix[row][i];
+  for(let i=0;i<col;i++) matrix[col][i] = (matrix[col][i]===cntr)? 0: matrix[col][i];
+
+  for(let i=row;i<matrix.length;i++) matrix[i][row] = (matrix[i][row]===cntr)? 0: matrix[i][row];
+  for(let i=col;i<matrix.length;i++) matrix[i][col] = (matrix[i][col]===cntr)? 0: matrix[i][col];
+
+  matrix[row][col] = 0;
+}
+
+function MakePairsV3(callback){
+  executeAPI(getAvailableNames,function(names,error){
+    if (error){
+      console.log("Error - could not load names");
+      callback.send({pairs: null, left: null, error: true, error_message: 'Could not load names list'});
+      return;
+    }
+    executeAPI(getPairs, function(pairs,error){
+      if (error){
+        console.log("Error - could not load pairs");
+        callback.send({pairs: null, left: null, error: true, error_message: 'Could not load pairs list'});
+        return;
+      }
+      max_pairs = Math.floor(names.length/2);
+      matrix=[];
+
       for (let i=0;i<names.length;i++){
-        next_i=false;
-        for (let j=0;j<names.length;j++){
-          if (i!=j){
-            
-            let found=false;
-            
-            pairs.filter((pair)=>{
-              if ((pair.name1==names[i] && pair.name2==names[j])||(pair.name1==names[j] && pair.name2==names[i])){
-                found=true;
-                return;
-              }
-            });
+        let matrix_row = [];
+        for (let j=0;j<=i;j++) (i===j)? matrix_row.push(1):matrix_row.push(0);
+        matrix.push(matrix_row);
+      }
 
-            if (!found){
-              usedNames.filter((name)=>{
-                if (names[i] === name || names[j] === name){
-                  found=true;
-                  return;
-                }
-              });
-            }
-            
+      //Mark existing pairs, put 3 in matrix fields 
+      pairs.filter((pair)=>{
 
-            if (!found){
-              next_i=true;
-              newPairs.push({name1:names[i], name2:names[j]});
-              usedNames.push(names[i]);
-              usedNames.push(names[j]);
-              break;
-            }
+        let name1_id = names.indexOf(pair.name1);
+        let name2_id = names.indexOf(pair.name2);
+
+        if (name1_id !== -1 && name2_id !== -1){
+          if (name1_id > name2_id){
+            matrix[name1_id][name2_id] = 3;
+          }else{
+            matrix[name2_id][name1_id] = 3;
           }
         }
-        if (next_i) continue;
+      });
+
+      tree = [];
+      done=false;
+
+      for (let i=0;i<names.length;i++){
+        for (let j=0;j<=i;j++){
+          if (matrix[i][j] === 0){
+            count_pairs(i,j,5);
+            if (done) break;
+          }
+        }
+        if (done) break;
       }
-      pairsForSave=newPairs;
-      callback.send(newPairs);
+
+      let max_count_index = 0;
+      
+      for (let i=0;i<tree.length;i++){
+        if (tree[i].length > tree[max_count_index].length)
+          max_count_index = i;
+      }
+
+      let result_pairs = [];
+      if (tree.length > 0){
+        for (let i=0;i<tree[max_count_index].length;i++){
+          result_pairs.push({name1: names[tree[max_count_index][i].row],name2: names[tree[max_count_index][i].col] });
+        }
+
+        let indexToRemove = [];
+
+        for (let i=0;i<tree[max_count_index].length;i++){
+          indexToRemove.push(tree[max_count_index][i].row);
+          indexToRemove.push(tree[max_count_index][i].col);
+        }
+
+        indexToRemove.sort((a,b)=>{
+          if (a>b) return -1; else return 1;
+        });
+
+        for (let i=0;i<indexToRemove.length;i++)
+          names.splice(indexToRemove[i],1);
+      }
+
+      if (names.length === 0) names=null;
+      pairsForSave = result_pairs;
+      callback.send({pairs: result_pairs, left: names, error:false});
     });
   });
-  //Napravi par -> Provjeri da li postoji -> Snimi ili ponovi postupak
-
+  
 }
 
 function SavePairs(callback){
-  if (lastRow== null) return;
+  if (lastRow=== null) {
+    callback.send({result:true});
+    return;
+  }
 
   auth=oauth2Client;
 
@@ -220,6 +321,7 @@ function SavePairs(callback){
 
   const data = [];
 
+  if (lastRow === 0) lastRow=-1;
   let range1= '2017!A'+(lastRow+2)+':A'+(lastRow+2+pairsForSave.length);
   let range2= '2017!B'+(lastRow+2)+':B'+(lastRow+2+pairsForSave.length);
   
@@ -269,15 +371,13 @@ app.use(function(req, res, next) {
 app.get('/getPairs',(req,resp)=>{
   pairsForSave=[];
   lastRow=null;
-  MakePairs(resp);
+  MakePairsV3(resp);
 });
 
 app.get('/savePairs', (req,resp)=>{
   SavePairs(resp);
-  //resp.send({result:true});
 });
 
-
 app.listen(3005, function () {
-  console.log('server na portu 3005');
+  console.log("Server running - Port 3005");
 })
\ No newline at end of file
diff --git a/web/src/App.js b/web/src/App.js
index e54465ad..6e8163fa 100644
--- a/web/src/App.js
+++ b/web/src/App.js
@@ -18,10 +18,10 @@ class App extends Component {
   getPairsEventHandler = (event) =>{
     let url = `http://${BASE_URL}:3005/getPairs`;
     
-    this.setState({waitingPairs:true});
+    this.setState({waitingPairs:true, renderFinish:false, waitingSave:true});
     
     fetch(url, {}).then(function(response) { return response.json(); }).then(function(data) {
-      this.setState({pairs : data, renderPairsList:true, waitingPairs:false});
+      this.setState({pairs : data.pairs, left:data.left, renderPairsList:!data.error, waitingPairs:false, waitingSave:false, error: data.error, error_message: data.error_message});
     }.bind(this));
 
 
@@ -46,13 +46,32 @@ class App extends Component {
         <div className = "horizontalDiv">
           <button disabled={this.state.waitingPairs} onClick = {this.getPairsEventHandler}>Get pairs</button>
         </div>
-        <div>
-          <h2> List of pairs : </h2>
-        </div>
+        {
+          this.state.error &&
+          <div>
+            <h2> Error - {this.state.error_message} </h2>
+          </div>
+        }
+        {
+          this.state.renderPairsList &&
+          <div>
+            <h2> List of pairs : </h2>
+          </div>
+        }
         {
           this.state.renderPairsList &&
             <PairsListComponent pairs = {this.state.pairs}/>
         }
+        {
+          this.state.renderPairsList && this.state.left &&
+          <div>
+            <h2> Without pair : </h2>
+            {
+              this.state.left.map((name, index) =>
+              (<div key={name}>{index+1}. {name}</div>))
+            }
+          </div>
+        }
         {
           this.state.renderPairsList &&
             <button disabled={this.state.waitingSave} onClick = {this.savePairsEventHandler}> Save pairs </button>
diff --git a/web/src/PairComponent.js b/web/src/PairComponent.js
index e6dd674d..7987ff92 100644
--- a/web/src/PairComponent.js
+++ b/web/src/PairComponent.js
@@ -3,14 +3,14 @@ import React, { Component } from 'react';
 export default class PairComponent extends Component{
   constructor(props) {
     super(props);
-    this.state = {pairName: this.props.pair};
+    this.state = {pairName: this.props.pair, index: this.props.index};
   }
 
   render(){
     return (
       <div>
         <div className = "horizontalDiv">
-          <div>{this.state.pairName.name1} - {this.state.pairName.name2}</div>
+          <div>{this.state.index+1}. {this.state.pairName.name1} - {this.state.pairName.name2}</div>
         </div>
       </div>
     )
diff --git a/web/src/PairsListComponent.js b/web/src/PairsListComponent.js
index 9002b638..18032d0f 100644
--- a/web/src/PairsListComponent.js
+++ b/web/src/PairsListComponent.js
@@ -7,7 +7,7 @@ export default class PairsListComponent extends Component{
       <div id = "outerDiv">
         {
           this.props.pairs.map((pair, index) =>
-            (<PairComponent key = {index} index = {index} pair = {pair}/>))
+            (<PairComponent key = {pair.name1+pair.name2} index = {index} pair = {pair}/>))
         }
       </div>
     )