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