#include<iostream>
#include<cstdio>
using namespace std;
double a[15][15];
int main(){
    int c;
    cin>>c;
    char flag;
    cin>>flag;
    for(int i=1;i<=12;i++){
        for(int j=1;j<=12;j++){
            cin>>a[i][j];
        }
    }
    double sum = 0.0;
    for(int i=1;i<=12;i++) sum += a[i][c + 1];
    if(flag == 'S') printf("%.1lf",sum);
    else printf("%.1lf",sum/12);
}