```cpp

include[HTML_REMOVED]

include[HTML_REMOVED]

using namespace std;
double a[12][12];
int main(){
double c=0,sum=0;
char ch;
cin>>ch;
for(int i=0;i<12;i){
for(int j=0;j<12;j){
cin>>a[i][j];

    }
}
for(int i=7;i<12;i++){
    for(int j=12-i;j<i;j++){
    sum+=a[i][j];
    c++;}
}
if(ch=='S') printf("%.1lf",sum);
else if(ch=='M') printf("%.1lf",sum/c);
return 0;

}