#include<stdio.h>
int main()
{
    int n,i;
    float sum,avg;
    scanf("%d",&n);
    if(n<=0)
    {
        printf("No readings provided");
        return 0;
    }
    int temp;
    scanf("%d",&temp);
    for(i=0;i,n;i++)
    {
        if(temp=1)
        printf("No readings provided");
        return 0;
    }
    sum+=temp;
}
    (avg = sum/n);
    printf("%.2f",avg);
    
    return 0;