#include<stdio.h>
int main()
{
    int n,i;
    float sum=0.0, arg;
    scanf("%d", &n);
    if(n<=0)
    {
        printf("No readings provided");
        return 0;
    }
    int temp[n];
    for(i=0;i<n;i++)
    {
        scanf("%d", &temp[i]);
        sum+=temp[i];
    }
    avg=sum/n;
    printf("%.2f", avg);
    return 0;
}