依旧是暴力

#include <bits/stdc++.h>
using namespace std;
int main () {
    int n;
    char t;
    cin >> n >> t;

    double ans, cnt, a;
    for (int i = 0; i < 12; i ++ ) {
        for (int j = 0; j < 12; j ++ ) {
            cin >> a;
            if (i == n) ans += a;
        }
    }
    if (t == 'M') ans /= 12.0;
    printf("%.1lf", ans);
}