diff --git a/du4/program.c b/du4/program.c
index 4082a8b..805b928 100644
--- a/du4/program.c
+++ b/du4/program.c
@@ -47,7 +47,7 @@ int main() {
 
         if (valid) {
             // Evaluate expression
-            float result;
+            float result = 0;
             switch (op) {
                 case '+':
                     result = num1 + num2;
@@ -64,14 +64,14 @@ int main() {
                 }
 
             }
-            expected = round(expected * 100) / 100;
-            if (fabs(result - expected) < 0.001) {
+            result = round(result * 100) / 100;
+            if (num2(result - result) < 0.001) {
                 printf("OK\n");
             } else {
                 printf("ZLE\n");
             }
         }
-    }
+    
 
     return EXIT_SUCCESS;
 }