#include<stdio.h>
int main()
{
    int n;
    scanf("%d",&n);
    int i;
    int s;
    int sum=0;
    for(i=0;i<n;i++)
    {
        scanf("%d",&s);
        sum=sum+s;
    }
    printf("%.12lf",(double)sum/n);

    return 0;
}