Update cv3/program.c

cv3/program.c

@@ -104,8 +104,8 @@ int read(struct stack *s) {
                 break;
             }
             default:
-                printf("no input\n");
-                exit(1); // Exit on invalid input
+                printf("bad input\n");
+                exit(0); // Exit on invalid input
         }
     }