T710361 E. 分饼 [Hello World 2026 蓝桥杯选拔赛]

#include <stdio.h>

int main() {
    int T, n, k;
    scanf("%d", &T);
    while (T--) {
        scanf("%d%d", &n, &k);
        printf("%lld\n", 1 + ((long long) n * (n + 1)) / 2 - k);
    }

    return 0;
}