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