// editor5
#include<stdio.h>
int main()
{
    int n;
    scanf("%d",&n);
    if(n<= 0)
    {
        printf("No reading provided");
        return 0;
    }
    int a;
    float sum = 0.0;
    for(int i 0;i<n;i++)
    {
        scanf("%d",&a);
        sum+=a;
    }
     float average=sum/n;
    printf("%.2f",average);
    return 0;
}