diff --git a/bin/main/ch/fhnw/kry/SPN.class b/bin/main/ch/fhnw/kry/SPN.class
index 317df83..335e3cb 100644
Binary files a/bin/main/ch/fhnw/kry/SPN.class and b/bin/main/ch/fhnw/kry/SPN.class differ
diff --git a/src/main/java/ch/fhnw/kry/SPN.java b/src/main/java/ch/fhnw/kry/SPN.java
index a4a31db..b17ea73 100644
--- a/src/main/java/ch/fhnw/kry/SPN.java
+++ b/src/main/java/ch/fhnw/kry/SPN.java
@@ -62,13 +62,22 @@ public class SPN {
     }
 
     public int swapBits(int x, int a, int b) {
-        int tmpA = (x & (0x1 << 15 - a)) == 0 ? 0 : 1;
-        int tmpB = (x & (0x1 << 15 - b)) == 0 ? 0 : 1;
+        int tmpA = (x & (0x1 << (15 - a)));
+        int tmpB = (x & (0x1 << (15 - b)));
+        
+        tmpA = tmpA == 0 ? 0 : 1;
+        tmpB = tmpB == 0 ? 0 : 1;
 
-        x = tmpA == 0 ? (x & 0x1 << 15 - b) & 0b0 : (x & 0x1 << 15 - b) & ~0b0;
+        tmpA = tmpA << (15 -b);
+        tmpB = tmpB << (15 - a);
 
+        x = x | tmpA;
+        x = x | tmpB;
 
-        return 0;
+        // x = tmpA == 0 ? (x & 0x1 << 15 - b) | 0b0 : (x & 0x1 << 15 - b) | ~0b0;
+        // x = tmpB == 0 ? (x & 0x1 << 15 - a) | 0b0 : (x & 0x1 << 15 - a) | ~0b0;
+
+        return x;
     }
 
 }