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