#include<iostream>
#include<cstdio>

using namespace std;

int main()
{
    int N;
    char x;
    cin >> N >> x;

    double M[12][12] = {0};
    double n;

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

    double sum = 0;
    for(int i = 0;i < 12; i ++) sum += M[i][N];

    if(x=='S') printf("%.1lf",sum);
    else if(x=='M') printf("%.1lf",sum/12);

    return 0;
}