#include<stdio.h>
int main()
{
    int n;
     scanf("%d", &n);
     if(n<=0)
    {
        printf(" No readings provided);
        return 0;
    }
    int temp;
    float sum=0;
    for(int i=0;i<n;i++)
    {
        scanf("%d",& temp);
        sum += temp;
    }
    float avg=sum / n;
    printf("%0.2f",avg);
    return 0;
    }