#include <stdio.h>
int main (void){
    int i, h, n, s=0;
    double d;
    scanf ("%d", &h);
    for (i=0; i<h; i++){
        scanf ("%d", &n);
        s=s+n;
    }
    d = (double) s;
    
    printf ("%.2lf", d/h);
    return 0;
}