#include <stdio.h>
#include <stdlib.h>

int main(int argc, char **argv) {

    int n, i, cases, sum=0;
    scanf("%d", &cases);
    for(i = 0; i < cases; i++)
    {
        scanf("%d",&n);
        sum+=n;
    }
    printf("%.2f\n",(float)sum/cases);

    return 0;
}