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