#include <cstdio>

int main()
{
    double a[12][12];
    int l;
    char t;

    scanf("%d\n%c", &l, &t);

    for(int i = 0; i < 12; i++)
    {
        for (int j = 0; j < 12; j++)
        {
            scanf("%lf", &a[i][j]);
        }
    }

    double s = 0;
    for (int i = 0; i < 12; i++) s += a[l][i];

    if (t == 'S') printf("%.1lf\n", s);
    else if (t == 'M') printf("%.1lf\n", s/12);

    return 0;
}