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