#include<stdio.h>
int main()
{
    int n,i,num,sum = 0;
    scanf("%d", &n);
    if(n ==0)
    {
        printf("No readings provided");
        return 0;
    }
    int readinds[100];
    for (i = 0; i < n; i++)
    {
        scanf("%d", &readings[i]);
        sum += readings[i];
    }
    printf("%.2f",(float)sum / n);
    return 0;
}