include[HTML_REMOVED]

int main()
{

char c;
scanf("%c",&c);
double a[12][12];
for(int i =0;i<12;i++){
    for(int j =0;j<12;j++)
    {
        scanf("%lf",&a[i][j]);
    }
}

double sum;
double average;

for(int i =0;i<12;i++)
{

for(int j =0;j<12;j++)
{
    if(j+i<11)
  sum += a[i][j];
}

}

if(c=='S') {
    printf("%.1lf",sum);
}else if(c=='M'){
    printf("%.1lf",sum/66);
}


return 0;

}
//i+j<11