#include <iostream>

using namespace std;

double arr[12][12];
double sum;

int main(void)
{
    int n;
    cin >> n;
    char op;
    cin >> op;

    for (int i = 0; i < 12; i++) {
        for (int j = 0; j < 12; j++) {
            cin >> arr[i][j];
            if (i == n) sum += arr[i][j];
        }
    }

    if (op == 'S') printf("%.1f\n", sum);
    else printf("%.1f\n", sum / 12);

    return 0;
}