#include<stdio.h>
int main()
{
    int n, i;
    float sum =0.0 avg;
    scanf("%d", &n);
    if(n <=0){
        printf("No readings provaid");
        return 0;
    }
    iint temp[n];
    for(i=0;i<n;i++){
        scanf("%d", &temp[i]);
        sum += temp[i];
    }
    avg = sum/n;
    printf("%.2f", avg);
    return 0;
}