#include <stdio.h>
int main()
{
    int n , i ,sum =  0;
    int arr[n];
    scanf("%d",&n);
    double ave ;
    for(i=0;i<n;i++)
    {
        scanf("%d",&arr[i]);
        sum += arr[i];
    }
    ave =  sum*1.0 / n;
    printf("%.2lf",ave);
    return 0 ;
}