diff --git a/src/RomanNumerals.java b/src/RomanNumerals.java
index 20904f0..37200f0 100644
--- a/src/RomanNumerals.java
+++ b/src/RomanNumerals.java
@@ -1,8 +1,123 @@
 
-public class RomanNumerals {
-	public int convertToInteger(String romanNum) {
-		// To be Implemented
+/* 
+The	symbols	'I',	'X',	'C',	and	'M'	can	be	repeated	at	most	3	times	in	a row.
+The	symbols	'V',	'L',	and	'D'	can	never	be repeated.
+The '1' symbols ('I', 'X', and 'C') can only be subtracted from the 2 next highest values ('IV' and	
+'IX',	'XL'	and	'XC',	'CD'	and 'CM').
+Only	one	subtraction	can	be	made	per	numeral	('XC'	is	allowed,	'XXC'	is not).
+The	'5'	symbols	('V',	'L',	and	'D')	can	never	be subtracted.
+ */
+
+public class RomanNumerals 
+{
+	
+	public int convertToInteger(String romanNum) 
+		{
+		// in case someone sends small letters that we use for
+		// other purposes in the program
+		romanNum = romanNum.toUpperCase(); 
+		// checks that the 2 / 4 same letter combo is not present 
+		if(!checkValidity(romanNum)) return -1;
+		// checks that IXC can be deducted only from two next letters
+		if(!illegalCombos(romanNum)) return -1;
+		// changes substracted IXC values of VXLDM to vxlcdm whcih stand for 4, 9, 40, 90, 400 and 900
+		romanNum=cheatCalculation(romanNum);
+		// counts the total
+		return sumUp(romanNum);
+		}
+	
+	public int convertOne(char x)
+		{
+		switch (x)
+			{
+		case 'I' : return 1;
+		case 'v' : return 4;
+		case 'V' : return 5;
+		case 'x' : return 9;
+		case 'X' : return 10;
+		case 'l' : return 40;
+		case 'L' : return 50;
+		case 'c' : return 90;
+		case 'C' : return 100;
+		case 'd' : return 400;
+		case 'D' : return 500;
+		case 'm' : return 900;
+		case 'M' : return 1000;
+			}
 		return 0;
+		}
+	
+	public int sumUp(String rNum)
+		{
+		int sum=0;
+		for (int i=0; i<rNum.length(); i++)
+			{
+			sum=sum+convertOne(rNum.charAt(i));			
+			}
+		return sum;
+		}
+	
+	public String cheatCalculation(String x)
+		{
+		x=x.replace("IV","v");
+		x=x.replace("IX","x");
+		x=x.replace("XL","l");
+		x=x.replace("XC","c");
+		x=x.replace("CD","d");
+		x=x.replace("CM","m");
+		return x;
+		}
+	
+	public boolean checkValidity(String x)
+	
+		{
+		int i, j;
+		String rNumerals="VLDIXCM";
+		String target="";
+		char tested=rNumerals.charAt(0); // Would not allow me to introduce it without value
+		for (i=0; i<rNumerals.length(); i++)
+			{
+			tested=rNumerals.charAt(i);
+			if (i<3) 
+				{
+				target=target+tested+tested;
+				}
+			else
+				{
+				for (j=0; j<4; j++)
+					{
+					target=target+tested;
+					}
+				}
+			if (x.contains(target)) return false;
+			target="";
+			}
+		return true;
+		}
+	
+	public boolean illegalCombos(String x)
+		{
+		String rNumerals = "IXC";
+		String [] comparison = new String[3];
+		comparison[0]="IVX";
+		comparison[1]="XILC";
+		comparison[2]="CIXDM";
 		
-	}
+		int i, j;
+		for (i=0; i<x.length()-1; i++) // will not test the last letter for substractor
+			{
+			// find which of the substractor Roman numerals it is if any
+			for (j=0; j<rNumerals.length(); j++)
+				{
+				if (x.charAt(i) == rNumerals.charAt(j))
+					{
+					// this should help to check if the letter is included in the comparison table
+					if (comparison[j].indexOf(x.charAt(i+1)) ==-1) return false;
+					}
+										
+				}
+			}
+		return true;
+		}
+	
 }
diff --git a/tests/TestRomanNumerals.java b/tests/TestRomanNumerals.java
index 5d1de75..0ef6f13 100644
--- a/tests/TestRomanNumerals.java
+++ b/tests/TestRomanNumerals.java
@@ -2,11 +2,75 @@
 
 import org.junit.Test;
 
-public class TestRomanNumerals {
+public class TestRomanNumerals 
+{
 
 	@Test
-	public void test() {
-		fail("Not yet implemented");
-	}
+	public void test_calculation_of_Roman_Numerals() 
+		{
+		String year = "MCMLXXXIV";
+		int result = 0;
+		RomanNumerals x = new RomanNumerals();
+		result = x.convertToInteger(year);
+		if (result == -1) fail ("The Roman number had illegal letter combos in it");
+		if (result != 1984) fail("Numbers do not match");
+		}
 
+	@Test
+	public void testIndividualLetters() 
+		{
+		String letters="IVXCLM";
+		RomanNumerals x = new RomanNumerals();
+		for (int i=0; i<6; i++)
+			{
+			// char letter = letters.charAt(i);
+			
+			if (x.convertOne(letters.charAt(i)) == 0) fail("Wrong result for individual letter convert test");
+			}
+		}
+	
+	@Test
+	public void testSum_without_considering_the_places_in_string() 
+		{
+		String year = "MCMLXXXIV";
+		RomanNumerals x = new RomanNumerals();
+		if (x.sumUp(year) != 2186) fail("Did not compute correctly");
+		}
+	
+	@Test
+	public void test_cheatCalculation()
+	{
+	String year = "CMCDXCXLIXIV";
+	RomanNumerals x = new RomanNumerals();
+	year = x.cheatCalculation(year);
+	}
+	
+	@Test
+	public void test_checkValidity() // If there are more than 3 x of specific letter or 2 x of another
+	{
+	// Select which failure to test	
+	// String year = "MMMM";
+	// String year = "DD";
+	// String year = "CCCC";
+	// String year = "LL";
+	// String year = "XXXX";
+	// String year = "VV";
+	String year = "IIII";
+	RomanNumerals x = new RomanNumerals();
+	// char result = x.checkValidity(year);
+	if (!x.checkValidity(year)) fail ("Fails because too many (2 / 4) Roman numerals of type in a row");
+	}
+	
+	
+	@Test
+	public void test_illegalCombos()
+	{
+	// String year="IX"; // should work	
+	// String year="IC"; // should fail
+	// String year = "MCMLXXXIV"; // should work
+	String year = "MXMLXXXIV"; // should fail
+	RomanNumerals x = new RomanNumerals();
+	if (!x.illegalCombos(year)) fail ("Wrong roman numeral combos detected");
+	}
+	
 }