//
// Created by lan on 2024/3/29.
//
数组的右上半部分
#include <cstdio>
int main() {
char c;
scanf("%c", &c);
double a[12][12];
for (int i = 0; i < 12; i++) {
for (int j = 0; j < 12; j++) {
scanf("%lf", &a[i][j]);
}
}
double sum = 0;
int count = 0;
for (int i = 0; i < 12; i++) {
for (int j = i + 1; j < 12; j++) {
count++;
sum += a[i][j];
}
}
if (c == 'S') printf("%.1lf", sum);
else printf("%.1lf", sum / count);
return 0;
}