diff --git a/du4/program.c b/du4/program.c
index c2df95b..afbee1a 100644
--- a/du4/program.c
+++ b/du4/program.c
@@ -34,7 +34,12 @@ int main() {
                     operation = 1;
                     break;
                 case '-':
-                    operation = 2;
+                    if(operation == 0)
+                        operation = 2;
+                    else{
+                        result[strlen(result)] = symbol;
+                        result[strlen(result)] = '\0';
+                    }
                     break;
                 case '*':
                     operation = 3;