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