add fatall error compilation

main.cpp

@@ -3,7 +3,7 @@
 int main() {
     int sum = 0;
     for (int i = 1; i <= 100; i++) {
-        sum += i;
+        sum += is
     }
     std::cout << "The sum of numbers from 1 to 100 is: " << sum << std::endl;
     return 0;