#include <stdio.h>

int main() {
    int n;
    scanf("%d", &n);
    
    if (n == 0) {
        printf("No readings provided");
        return 0;
    }
    int temp;
    double sum = 0;
    
    for (int i = 0; i < n; i++) {
        scanf("%d", &temp);
        sum += temp;
    }
    double avg = sum / n;
    
    printf("%.2f", average);
    
    return 0;
}