import java.io.;
import java.util.;
public class Main{
public static void main(String args[]) throws Exception{
var M = new double[12][12];
Scanner cin = new Scanner(System.in);
var L = cin.nextInt();
var c = cin.next().charAt(0); //Java中读入单个字符的方法
for (int i = 0; i < 12; i++){
for(int j = 0; j < 12; j++){
M[i][j] = cin.nextDouble();
}
}
double s = 0;
for(int i = 0; i < 12; i++){
s += M[L][i];
}
if(c == 'S'){ //Java识别单个字符
System.out.printf("%.1f\n",s);
}
else{
System.out.printf("%.1f\n",s/12);
}
}
}