diff --git a/njvm.c b/njvm.c
index da44212..8e2c6b9 100644
--- a/njvm.c
+++ b/njvm.c
@@ -2,6 +2,10 @@
 #include <string.h>
 #include <stdlib.h>
 
+//Comment to disable debug
+
+#define DEBUG
+
 #define IMMEDIATE(x) ((x) & 0x00FFFFFF)
 
 #define HALT 0
@@ -72,14 +76,19 @@ void execute(void) {
             case PUSHC:
                 break;
             case ADD:
+                  stackPush(stackPop()+stackPop());
                 break;
             case SUB:
+                  stackPush(stackPop()-stackPop());
                 break;
             case MUL:
+                  stackPush(stackPop()*stackPop());
                 break;
             case DIV:
+                  stackPush(stackPop()/stackPop());
                 break;
             case MOD:
+                  stackPush(stackPop()%stackPop());
                 break;
             case RDINT:
                 break;
@@ -93,8 +102,18 @@ void execute(void) {
         i++;
     }
 }
+#ifdef DEBUG
+
+void tests(){
+   printf("test\n"); 
+}
+
+#endif /* ifdef DEBUG */
 
 int main(int argc, char *argv[]) {
+    #ifdef DEBUG
+      tests();
+    #endif /* ifdef DEBUG */
     if (argc > 1) useption(argc, argv);
     else {