#include<stdio.h>
int main()
{
    int row,i,j;
    double m[12][12];
    char ch;
    double n,sum=0,avg;

    scanf("%d",&row);
    scanf("%s",&ch);

    for(i=0;i<12;i++){
        for(j=0;j<12;j++){
            scanf("%lf",&n);
            m[i][j]=n;
        }
    }

    if(ch=='S'){
        for(i=0;i<12;i++){
            sum+=m[row+1][i];
        }
        printf("%0.1lf\n",sum);
    }

    else if(ch=='M'){
        for(i=0;i<12;i++){
            sum+=m[row+1][i];
            avg=(sum/12);
        }
        printf("%0.1lf\n",avg);
    }


    return 0;
}