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