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