import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int l = sc.nextInt();
String op = sc.next();
double[][] w = new double[12][12];
for (int i = 0; i < 12; i ++)
for (int j = 0;j < 12; j ++)
w[i][j] = sc.nextDouble();
double sum = 0;
for (int i = 0; i < 12; i ++)
sum += w[l][i];
if (op.equals("M")) sum /= 12;
System.out.printf("%.1f", sum);
}
}