diff --git a/code/roman-numerals/src/main/java/fr/istic/vv/RomanNumeraUtils.java b/code/roman-numerals/src/main/java/fr/istic/vv/RomanNumeraUtils.java
index a37e18a..857046c 100644
--- a/code/roman-numerals/src/main/java/fr/istic/vv/RomanNumeraUtils.java
+++ b/code/roman-numerals/src/main/java/fr/istic/vv/RomanNumeraUtils.java
@@ -1,11 +1,154 @@
 package fr.istic.vv;
 
+import java.util.HashMap;
+import java.util.Map;
+
 public class RomanNumeraUtils {
+
+    final static Map<Character, Integer> mapToNum = new HashMap<>();
+    static {
+        mapToNum.put('M', 1000);
+        mapToNum.put('D', 500);
+        mapToNum.put('C', 100);
+        mapToNum.put('L', 50);
+        mapToNum.put('X', 10);
+        mapToNum.put('V', 5);
+        mapToNum.put('I', 1);
+    }
+
+    public static boolean isValidRomanNumeral(String value) {
+        boolean isValid = true;
+        
+        char lastChar = ' ';
+        int nbLastChar = 0;
+        int valMax = 1001;
+
+        for(int i = 0; i<value.length() && isValid; i++){
+
+            char val = value.charAt(i);
+
+            if(mapToNum.containsKey(val) && mapToNum.get(val)<valMax){
+                if(lastChar!=' '){
+                    if(mapToNum.get(val)>mapToNum.get(lastChar)){
+                        //seul I X C peuvent soustraire un symbole (ex : IX XC CM)
+                        if(lastChar == 'I' || lastChar == 'X' || lastChar == 'C'){
+                            valMax = mapToNum.get(lastChar)-1;
+                            //si plus de 1 soustraction (ex IIX) ou que la soustraction est ni 1/10 ni 1/5 du chiffre le plus grand
+                            if(nbLastChar>1 || !(mapToNum.get(val)/10==mapToNum.get(lastChar) || mapToNum.get(val)/5==mapToNum.get(lastChar))){
+                                isValid = false;
+                            }
+                        }
+                        else isValid = false;
+                    }
+
+                }
+                switch (val){
+                    case 'M':
+                    case 'C':
+                    case 'X':
+                    case 'I':
+                        if(lastChar==value.charAt(i)){
+                            nbLastChar++;
+                            if(nbLastChar>3) isValid = false;
+                        }
+                        else{
+                            lastChar = value.charAt(i);
+                            nbLastChar = 1;
+                        }
+                        break;
+                    case 'D':
+                    case 'L':
+                    case 'V':
+                        if(lastChar==value.charAt(i)){
+                                nbLastChar++;
+                                if(nbLastChar>1) isValid = false;
+                        }
+                        else{
+                                lastChar = value.charAt(i);
+                                nbLastChar = 1;
+                        }
+                        break;
+                    default:
+                        isValid = false;
+                }
+            }
+            else isValid = false;
+        }
+
+        return isValid;
+    }
+
+    public static int parseRomanNumeral(String numeral) {
+        if(isValidRomanNumeral(numeral)){
+            
+            int res = 0;
+            char lastChar = ' ';
+
+            for(int i = 0; i<numeral.length(); i++){
+
+                char val = numeral.charAt(i);
+                int value = mapToNum.get(val);
+                                                                                        // -
+                if(i+1<numeral.length() && mapToNum.get(numeral.charAt(i+1))>value){    //XIX
+                    res += 0;
+                }                                                       // -
+                else if(lastChar!=' ' && value>mapToNum.get(lastChar)){ //IX
+                    res += value-mapToNum.get(lastChar);
+                }
+                else{
+                    res +=mapToNum.get(val);
+                }
+                lastChar = val;
+            }
+            return res;
+        }
+        else throw new IllegalArgumentException("Invalid date");
+
+    }
+
+    public static String toRomanNumeral(int number) {
+        System.out.println(number);
+        String res = "";
+        char[] order = {'M','D','C','L','X','V','I'};
+        char[] sub = {'I','X','C'};
+        if(number<4000){
+            while(number>0){
+                boolean notFound = true;
+                for(int i = 0; i<order.length&&notFound; i++){
+                    char symb = order[i];
+                    int val = mapToNum.get(symb);
+
+                    if(number>=val){
+                        number -= val;
+                        res = res + symb;
+                        System.out.println(res);
+                        notFound = false;
+                    }
+                    else{
+                        boolean notFoundSub = true;
+                        for(int j = 0; j<sub.length&&notFoundSub; j++){
+                            char symbSub = sub[j];
+                            int valSub = mapToNum.get(symbSub);
+                            if(valSub*5==val || valSub*10==val){
+                                if(number>=val-valSub){
+                                    number -= val-valSub;
+                                    res = res + symbSub + symb;
+                                    System.out.println(res);
+                                    notFoundSub = false;
+                                    notFound = false;
+                                }
+                            }
+                            
+                        }
+                    }
+
+                }
+            }
+            System.out.println("Return : " + res);
+            return res;
+        }
+        else throw new IllegalArgumentException("max 4000");
     
-        public static boolean isValidRomanNumeral(String value) { return false; }
-    
-        public static int parseRomanNumeral(String numeral) { return 0; }
-    
-        public static String toRomanNumeral(int number) { return ""; }
-    
+    }
+
 }
diff --git a/code/roman-numerals/src/test/java/fr/istic/vv/RomanNumeralTest.java b/code/roman-numerals/src/test/java/fr/istic/vv/RomanNumeralTest.java
index ded8e7a..c3b9972 100644
--- a/code/roman-numerals/src/test/java/fr/istic/vv/RomanNumeralTest.java
+++ b/code/roman-numerals/src/test/java/fr/istic/vv/RomanNumeralTest.java
@@ -1,8 +1,120 @@
 package fr.istic.vv;
 import net.jqwik.api.*;
 import net.jqwik.api.constraints.IntRange;
+import static fr.istic.vv.RomanNumeraUtils.*;
 
 public class RomanNumeralTest {
+
+
+
+    @Example
+    void simpleValidRomanNumerals() {
+        assert isValidRomanNumeral("I");
+        assert isValidRomanNumeral("II");
+        assert isValidRomanNumeral("III");
+        assert isValidRomanNumeral("IV");
+        assert isValidRomanNumeral("VI");
+        assert isValidRomanNumeral("VIII");
+        assert isValidRomanNumeral("IX");
+        assert isValidRomanNumeral("X");
+        assert isValidRomanNumeral("XI");
+        assert isValidRomanNumeral("MI");
+        assert isValidRomanNumeral("XIII");
+    }
+
+    @Example
+    void nonValidRomanNumeralsBadLetter() {
+        assert !isValidRomanNumeral("IIIA");
+        assert !isValidRomanNumeral("A");
+        assert !isValidRomanNumeral("CAI");
+    }
+
+    @Example
+    void nonValidRomanNumeralsRepeated() {
+        assert !isValidRomanNumeral("IIII");
+        assert !isValidRomanNumeral("XXXX");
+        assert !isValidRomanNumeral("CCCC");
+        assert !isValidRomanNumeral("MMMM");
+        assert !isValidRomanNumeral("DD");
+        assert !isValidRomanNumeral("LL");
+        assert !isValidRomanNumeral("VV");
+    }
+
+    @Example
+    void validRomanNumeralsLeftSub() {
+        assert isValidRomanNumeral("IV");
+        assert isValidRomanNumeral("IX");
+        assert isValidRomanNumeral("XL");
+        assert isValidRomanNumeral("XC");
+        assert isValidRomanNumeral("CD");
+        assert isValidRomanNumeral("CM");
+        
+    }
+
+    @Example
+    void nonValidRomanNumeralsLeftSub() {
+        assert !isValidRomanNumeral("VX");
+        assert !isValidRomanNumeral("VL");
+        assert !isValidRomanNumeral("IL");
+        assert !isValidRomanNumeral("IC");
+        assert !isValidRomanNumeral("VC");
+        assert !isValidRomanNumeral("LC");
+        assert !isValidRomanNumeral("ID");
+        assert !isValidRomanNumeral("VD");
+        assert !isValidRomanNumeral("XD");
+        assert !isValidRomanNumeral("LD");
+        assert !isValidRomanNumeral("IM");
+        assert !isValidRomanNumeral("VM");
+        assert !isValidRomanNumeral("XM");
+        assert !isValidRomanNumeral("LM");
+        assert !isValidRomanNumeral("DM");
+    }
+
+    @Example
+    void completValidRomanNumerals() {
+        assert isValidRomanNumeral("MCDXXXIV");
+        assert isValidRomanNumeral("DCCLXXXIX");
+        assert isValidRomanNumeral("LXIX");
+        assert isValidRomanNumeral("MCCXXXIV");
+
+    }
+
+    @Example
+    void completNonValidRomanNumerals() {
+        assert !isValidRomanNumeral("IXX");
+        assert !isValidRomanNumeral("IXIXIX");
+        assert !isValidRomanNumeral("MMMDCCCLIXXXVIII");
+        assert !isValidRomanNumeral("XIXV");
+
+    }
+    
+
+    @Example
+    void testParseRomanNumeral() {
+        assert parseRomanNumeral("XX")==20;
+        assert parseRomanNumeral("XIX")==19;
+        assert parseRomanNumeral("XXI")==21;
+        assert parseRomanNumeral("IX")==9;
+        assert parseRomanNumeral("MCCXXXIV")==1234;
+    }
+
+
+
+
+        @Example
+    void testToRomanNumeral() {
+        assert toRomanNumeral(20).compareTo("XX")==0;
+        assert toRomanNumeral(19).compareTo("XIX")==0;
+        assert toRomanNumeral(21).compareTo("XXI")==0;
+        assert toRomanNumeral(9).compareTo("IX")==0;
+        assert toRomanNumeral(1234).compareTo("MCCXXXIV")==0;
+        assert toRomanNumeral(3999).compareTo("MMMCMXCIX")==0;
+    }
+
+
+
+
+
     @Property
     boolean absoluteValueOfAllNumbersIsPositive(@ForAll @IntRange(min=Integer.MIN_VALUE +1) int anInteger) {
         return Math.abs(anInteger) >= 0;
diff --git a/code/roman-numerals/target/classes/fr/istic/vv/RomanNumeraUtils.class b/code/roman-numerals/target/classes/fr/istic/vv/RomanNumeraUtils.class
index 9cae7b4..72c1d5f 100644
Binary files a/code/roman-numerals/target/classes/fr/istic/vv/RomanNumeraUtils.class and b/code/roman-numerals/target/classes/fr/istic/vv/RomanNumeraUtils.class differ
diff --git a/code/roman-numerals/target/test-classes/fr/istic/vv/RomanNumeralTest.class b/code/roman-numerals/target/test-classes/fr/istic/vv/RomanNumeralTest.class
index 6884cff..6e32f2f 100644
Binary files a/code/roman-numerals/target/test-classes/fr/istic/vv/RomanNumeralTest.class and b/code/roman-numerals/target/test-classes/fr/istic/vv/RomanNumeralTest.class differ