#include <stdio.h>
#include <stdlib.h>

int main() {
    double media, sum = 0;
    int n;

    scanf("%d", &n);
    int *p;
    p = malloc(n * sizeof(int));

    for(int i = 0; i < n; i++){
        scanf("%d", &p[i]);
        sum += p[i];
    }

    media = sum / n;
    printf("%.2f", media);

    free(p);
}