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