#include<iostream>

using namespace std;

int main()
{
    char c;
    cin >> c;

    double a[12][12];
    for(int i = 0;i < 12;i ++)
        for(int j = 0;j < 12;j ++) cin >> a[i][j];

    double sum = 0;
    for(int j = 0;j < 12;j ++)
        for(int i = j + 1;i < 11 - j;i ++) //相较于749 可以把行和列反过来看
        sum += a[i][j];

    if( c == 'S') printf("%.1lf\n",sum);
    if( c == 'M') printf("%.1lf\n",sum / 30);

    return 0;
}