#include<stdio.h>
float average
{
    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;
    }
    printf("%0.2f",average);
    return 0;
}