//
// Created by lan on 2024/3/30.
//
数组的做下半部分
#include <iostream>
#include <cstdio>
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 count = 0, sum = 0;
for (int i = 0; i <= 11; i++) {
for (int j = 0; j <= i - 1; j++) {
count += 1;
sum += a[i][j];
}
}
if (c == 'S') printf("%.1lf", sum);
else printf("%.1lf", sum / count);
return 0;
}