diff --git a/app/src/main/java/sudoku/structure/Difficulty.java b/app/src/main/java/sudoku/structure/Difficulty.java
index 9f0b225..a39615d 100644
--- a/app/src/main/java/sudoku/structure/Difficulty.java
+++ b/app/src/main/java/sudoku/structure/Difficulty.java
@@ -3,10 +3,10 @@ package sudoku.structure;
 //TODO: melvyn va passer par là
 public enum Difficulty {
 
-	VeryEasy("Très facile", 0.1), Easy("Facile", 0.25), Medium("Moyen", 0.5), Hard("Difficile", 0.75);
+	VeryEasy("Très facile", 0.1), Easy("Facile", 0.25), Medium("Moyen", 0.5), Hard("Difficile", 0.75), VeryHard("Impossible", 0.78);
 
-	double factor;
-	String displayName;
+	final double factor;
+	final String displayName;
 
 	private Difficulty(String displayName, double factor) {
 		this.factor = factor;
diff --git a/app/src/main/java/sudoku/structure/SudokuFactory.java b/app/src/main/java/sudoku/structure/SudokuFactory.java
index 4d970d1..0375426 100644
--- a/app/src/main/java/sudoku/structure/SudokuFactory.java
+++ b/app/src/main/java/sudoku/structure/SudokuFactory.java
@@ -145,7 +145,7 @@ public class SudokuFactory {
 			cellsThatCanBeEmptied.remove(cellToEmpty);
 		}
 
-		return false;
+		return newDokuFromFilledOne(doku, --nbCellsToEmpty);
 	}
 
 	/**