uncertain

/*
 Author: Cao Beijian
 Result: AC Submission_id: 4265184
 Created at: Thu Mar 31 2022 11:12:28 GMT+0800 (China Standard Time)
 Problem_id: 5441   Time: 3 Memory: 2220
*/

#include <stdio.h>
#include <math.h>
int main(){
    double a[1024] = { 0 }, avg = 0.0, unc = 0.0;
    int n = 0, i;
    while(~scanf("%lf", a + n)){
        avg += a[n];
        n++;
    }
    avg /= n;
    for(i = 0;i < n;i++){
        unc += (a[i] - avg) * (a[i] - avg);
    }
    unc = sqrt(unc / (n * (n - 1)));
    printf("%.4f %.4f\n", avg, unc);
    return 0;
}