#include<stdio.h>
float avg(float n,float sum)
{
    float avg=sum/n;
    return avg;
}
int main()
{
    int a,sum=0;
    int n;
    scanf("%d",&n);
    if(n==0)
    {
        printf("No readings provided");
        return 0;
    }
    for(int i=1;i<=n;i++)
    scanf("%d",&a);
    sum+=a;
}
int n,sum;
float c=avg(n,sum);
printf("%0.2f",c);
}