被这道题卡了好久，我是废物呜呜呜QAQ

#include <iostream>
#include <stdio.h>

int main() {
    int a, n;
    scanf("%d%d", &a, &n);
    while (n <= 0) {
        scanf("%d", &n);
    }
    int sum = 0;
    for (int i = 0; i < n; i++) {
        sum += a++;
    }
    printf("%d", sum);
}