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);
}
}