diff --git a/merger.js b/merger.js
index a02b3b4..0dfedc6 100644
--- a/merger.js
+++ b/merger.js
@@ -18,109 +18,90 @@
 
  ------------------------------------------------------------------------- */
 
-var utils = require('./utils.js');
-var actions = require('./actions.js');
-
-Main();
-
-function Main() {
-	const params = GetParams();
-	console.log(params);
-	var oldData = "";
-	var sum = 0;
-
-	var r = ReadData(utils.ReadFile(params[0]));
-	console.log(r.result.toString());
-	console.log("\n\n");
-	console.log("errors:");
-	console.log(r.logs.join("\n"));
-
-	/*for (var i = 0; i < params.length; i++) {
-		const data = utils.ReadFile(params[i]);
-	}
-	console.log("-------------");
-	console.log("Sum: " + sum);
-	console.log("Simplifying...");
-	var newData = Simplify(oldData);
-	var nr = actions.NLoad(newData);
-	console.log("New result: " + nr.count);
-	utils.WriteFile(newData, "newData");
-	console.log("File written!");*/
-}
-
-function GetParams() {
-	return process.argv.splice(2);
-}
-
 /*Question object
  * q: question
  * a: answer
  * i: image
  * */
-function Question(q, a, i) {
-	this.Q = q;
-	this.A = a;
-	this.I = i;
-	this.toString = function() {
+class Question {
+	constructor(q, a, i) {
+		this.Q = q;
+		this.A = a;
+		this.I = i;
+	}
+	toString() {
 		var r = "?" + this.Q + "\n!" + this.A;
 		if (this.I)
 			r += "\n>" + this.I;
 		return r;
-	};
-	this.HasQuestion = function() {
+	}
+	HasQuestion() {
 		return this.Q != undefined;
-	};
-	this.HasAnswer = function() {
+	}
+	HasAnswer() {
 		return this.A != undefined;
-	};
-	this.HasImage = function() {
+	}
+	HasImage() {
 		return this.I != undefined;
-	};
-	this.IsComplete = function() {
+	}
+	IsComplete() {
 		return this.HasQuestion() && this.HasAnswer();
-	};
-	this.Compare = function(q2) {
-		const qmatchpercent = CompareString(this.Q, q2.Q);
-		const amatchpercent = CompareString(this.A, q2.A);
-		const imatchpercent = I ? CompareString(this.I, q2.I) : 0;
-
-		return (qmatchpercent + amatchpercent + imatchpercent) / 3;
-	};
-	const CompareString = function(s1, s2) {
+	}
+	Compare(q2) {
+		const qmatchpercent = Question.CompareString(this.Q, q2.Q);
+		const amatchpercent = Question.CompareString(this.A, q2.A);
+		if (this.I != undefined) {
+			const imatchpercent = this.I == undefined ? Question.CompareString(this.I, q2.I) : 0;
+			return (qmatchpercent + amatchpercent + imatchpercent) / 3;
+		} else {
+			return (qmatchpercent + amatchpercent) / 2;
+		}
+	}
+	static CompareString(s1, s2) {
+		//if (s1 == undefined || s2 == undefined)
+		//	return 0;
 		s1 = SimplifyStringForComparison(s1).split(" ");
 		s2 = SimplifyStringForComparison(s2).split(" ");
 		var match = 0;
-		for (var i = 0; i < s1.length; i++) {
-			if (s2.includes(s1[i])) {
+		for (var i = 0; i < s1.length; i++)
+			if (s2.includes(s1[i]))
 				match++;
-			}
-		}
 		var percent = Math.round(((match / s1.length) * 100).toFixed(2)); // matched words percent
 		var lengthDifference = Math.abs(s2.length - s1.length);
 		percent -= lengthDifference * 3;
 		if (percent < 0)
 			percent = 0;
 		return percent;
-	};
+	}
 }
 
-function Subject(n) {
-	this.Name = n;
-	this.Questions = [];
-	this.AddQuestion = function(q) {
+class Subject {
+	constructor(n) {
+		this.Name = n;
+		this.Questions = [];
+	}
+	get length() {
+		return this.Questions.length;
+	}
+	AddQuestion(q) {
 		this.Questions.push(q);
-	};
-	this.toString = function() {
+	}
+	toString() {
 		var r = [];
 		for (var i = 0; i < this.Questions.length; i++)
 			r.push(this.Questions[i].toString());
 		return "+" + this.Name + "\n" + r.join("\n");
-	};
+	}
 }
 
-function QuestionDB() {
-	this.Subjects = [];
-	this.AddQuestion = function(subj, q) {
+class QuestionDB {
+	constructor() {
+		this.Subjects = [];
+	}
+	get length() {
+		return this.Subjects.length;
+	}
+	AddQuestion(subj, q) {
 		var i = 0;
 		while (i < this.Subjects.length && this.Subjects[i].Name != subj)
 			i++;
@@ -131,13 +112,60 @@ function QuestionDB() {
 			n.AddQuestion(q);
 			this.Subjects.push(n);
 		}
-	};
-	this.toString = function() {
+	}
+	AddSubject(subj) {
+		var i = 0;
+		while (i < this.length && subj.Name != this.Subjects[i].Name)
+			i++;
+
+		if (i < this.length) {
+			this.Subjects.concat(subj.Questions);
+		} else {
+			this.Subjects.push(subj);
+		}
+	}
+	toString() {
 		var r = [];
 		for (var i = 0; i < this.Subjects.length; i++)
 			r.push(this.Subjects[i].toString());
 		return r.join("\n\n");
-	};
+	}
+}
+var utils = require('./utils.js');
+var actions = require('./actions.js');
+
+Main();
+
+function Main() {
+	const params = GetParams();
+	console.log(params);
+	var dbs = [];
+
+	for (var i = 0; i < params.length; i++)
+		dbs.push(ReadData(utils.ReadFile(params[i])).result);
+
+	var db = MergeDatabases(dbs);
+
+	var r = RemoveDuplicates(db);
+
+	for (var i = 0; i < r.length; i++) {
+		console.log(r.Subjects[i].Name + ": " + r.Subjects[i].length + " darab kérdés.");
+	}
+
+	utils.WriteFile(JSON.stringify(r), "newData");
+	console.log("File written!");
+}
+
+function GetParams() {
+	return process.argv.splice(2);
+}
+
+function MergeDatabases(dbs) {
+	var db = new QuestionDB();
+	for (var i = 0; i < dbs.length; i++)
+		for (var j = 0; j < dbs[i].length; j++)
+			db.AddSubject(dbs[i].Subjects[j]);
+	return db;
 }
 
 /*
@@ -162,18 +190,24 @@ function ReadData(data) {
 			if (skipped >= 1)
 				logs.push(i + ": " + d[i]);
 			i++;
-			if (i >= d.length)
+			if (i >= d.length) {
+				if (currQuestion.IsComplete())
+					r.AddQuestion(currSubj, currQuestion);
 				return {
 					result: r,
 					logs: logs
 				};
+			}
 			currIdentifier = d[i][0];
 			skipped++;
 		} while (!ExpectedIdentifier.includes(currIdentifier) && i < d.length);
 
-		let currData = d[i].substring(1);
+		let currData = d[i].substring(1).trim();
 
 		if (currIdentifier == '+') {
+			if (currQuestion.IsComplete())
+				r.AddQuestion(currSubj, currQuestion);
+			currQuestion = new Question();
 			currSubj = currData;
 			ExpectedIdentifier = ['?'];
 			continue;
@@ -226,17 +260,34 @@ function ReadData(data) {
 	};
 }
 
-function SortQuestions(dataObj) {
-	/*
-	 * Sort questions by something
-	 * */
+function RemoveDuplicates(dataObj) {
+	for (var i = 0; i < dataObj.length; i++)
+		RemoveDuplFromSubject(dataObj.Subjects[i]);
+	return dataObj;
 }
 
-function RemoveDuplicates(dataObj) {
-	// TODO: compare and delete
-	/*
-	 * removes duplicates from a read data by comparing every question after sorting
-	 * */
+function RemoveDuplFromSubject(subj) {
+	var cp = subj.Questions;
+	subj.Questions = [];
+	for (var i = 0; i < cp.length; i++) {
+		var j = 0;
+		while (j < subj.length && cp[i].Compare(subj.Questions[j]) != 100) {
+			j++;
+		}
+		if (j < subj.length) {
+			//console.log("----------------------------------------------------------");
+			//console.log(cp[i].toString());
+			//console.log("  VS  ");
+			//console.log(subj.Questions[j].toString());
+			//console.log(cp[i].Compare(subj.Questions[j]));
+			//console.log(j);
+			//console.log("removed:");
+			//console.log(subj.Questions.splice(j, 1).toString());
+			//console.log("----------------------------------------------------------");
+		} else {
+			subj.AddQuestion(cp[i]);
+		}
+	}
 }
 
 function SimplifyStringForComparison(value) {