
import java.util.Scanner;

public class Main {
    static Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
        while (sc.hasNext()){
            int studentsNum = sc.nextInt();
            if (studentsNum == 0)
                break;
            double point[] = new double[studentsNum];
            double sum = 0;
            for (int i = 0; i < studentsNum; i++){
                point[i] = sc.nextInt();
                sum += point[i];
            }
            double ave = sum / studentsNum;
            double sm = 0;
            for (int j = 0; j < studentsNum; j++){
                sm += Math.pow(point[j] - ave, 2);
            }
            double aa = sm / studentsNum;
            double result = Math.sqrt(aa);
            System.out.println(result);
        }
    }
}
 import java.util.Scanner; Scanner java.util public class Main {
    static Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
        while (sc.hasNext()){
            int studentsNum = sc.nextInt();
            if (studentsNum == 0)
                break;
            double point[] = new double[studentsNum];
            double sum = 0;
            for (int i = 0; i < studentsNum; i++){
                point[i] = sc.nextInt();
                sum += point[i];
            }
            double ave = sum / studentsNum;
            double sm = 0;
            for (int j = 0; j < studentsNum; j++){
                sm += Math.pow(point[j] - ave, 2);
            }
            double aa = sm / studentsNum;
            double result = Math.sqrt(aa);
            System.out.println(result);
        }
    }
} Main static Scanner sc = new Scanner(System.in); sc new Scanner(System.in) public static void main(String[] args) {
        while (sc.hasNext()){
            int studentsNum = sc.nextInt();
            if (studentsNum == 0)
                break;
            double point[] = new double[studentsNum];
            double sum = 0;
            for (int i = 0; i < studentsNum; i++){
                point[i] = sc.nextInt();
                sum += point[i];
            }
            double ave = sum / studentsNum;
            double sm = 0;
            for (int j = 0; j < studentsNum; j++){
                sm += Math.pow(point[j] - ave, 2);
            }
            double aa = sm / studentsNum;
            double result = Math.sqrt(aa);
            System.out.println(result);
        }
    } main {
        while (sc.hasNext()){
            int studentsNum = sc.nextInt();
            if (studentsNum == 0)
                break;
            double point[] = new double[studentsNum];
            double sum = 0;
            for (int i = 0; i < studentsNum; i++){
                point[i] = sc.nextInt();
                sum += point[i];
            }
            double ave = sum / studentsNum;
            double sm = 0;
            for (int j = 0; j < studentsNum; j++){
                sm += Math.pow(point[j] - ave, 2);
            }
            double aa = sm / studentsNum;
            double result = Math.sqrt(aa);
            System.out.println(result);
        }
    } while (sc.hasNext()){
            int studentsNum = sc.nextInt();
            if (studentsNum == 0)
                break;
            double point[] = new double[studentsNum];
            double sum = 0;
            for (int i = 0; i < studentsNum; i++){
                point[i] = sc.nextInt();
                sum += point[i];
            }
            double ave = sum / studentsNum;
            double sm = 0;
            for (int j = 0; j < studentsNum; j++){
                sm += Math.pow(point[j] - ave, 2);
            }
            double aa = sm / studentsNum;
            double result = Math.sqrt(aa);
            System.out.println(result);
        } sc.hasNext() sc.hasNext sc {
            int studentsNum = sc.nextInt();
            if (studentsNum == 0)
                break;
            double point[] = new double[studentsNum];
            double sum = 0;
            for (int i = 0; i < studentsNum; i++){
                point[i] = sc.nextInt();
                sum += point[i];
            }
            double ave = sum / studentsNum;
            double sm = 0;
            for (int j = 0; j < studentsNum; j++){
                sm += Math.pow(point[j] - ave, 2);
            }
            double aa = sm / studentsNum;
            double result = Math.sqrt(aa);
            System.out.println(result);
        } int studentsNum = sc.nextInt(); studentsNum sc.nextInt() sc.nextInt sc if (studentsNum == 0)
                break; studentsNum == 0 studentsNum 0 break; double point[] = new double[studentsNum]; point new double[studentsNum] studentsNum double sum = 0; sum 0 for (int i = 0; i < studentsNum; i++){
                point[i] = sc.nextInt();
                sum += point[i];
            } int i = 0; int i = 0; i 0 i < studentsNum i studentsNum i++ i++ i {
                point[i] = sc.nextInt();
                sum += point[i];
            } {
                point[i] = sc.nextInt();
                sum += point[i];
            } point[i] = sc.nextInt() point[i] point i sc.nextInt() sc.nextInt sc sum += point[i] sum point[i] point i double ave = sum / studentsNum; ave sum / studentsNum sum studentsNum double sm = 0; sm 0 for (int j = 0; j < studentsNum; j++){
                sm += Math.pow(point[j] - ave, 2);
            } int j = 0; int j = 0; j 0 j < studentsNum j studentsNum j++ j++ j {
                sm += Math.pow(point[j] - ave, 2);
            } {
                sm += Math.pow(point[j] - ave, 2);
            } sm += Math.pow(point[j] - ave, 2) sm Math.pow(point[j] - ave, 2) Math.pow Math point[j] - ave point[j] point j ave 2 double aa = sm / studentsNum; aa sm / studentsNum sm studentsNum double result = Math.sqrt(aa); result Math.sqrt(aa) Math.sqrt Math aa System.out.println(result) System.out.println System.out System System.out result String[] args args public class Main {
    static Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
        while (sc.hasNext()){
            int studentsNum = sc.nextInt();
            if (studentsNum == 0)
                break;
            double point[] = new double[studentsNum];
            double sum = 0;
            for (int i = 0; i < studentsNum; i++){
                point[i] = sc.nextInt();
                sum += point[i];
            }
            double ave = sum / studentsNum;
            double sm = 0;
            for (int j = 0; j < studentsNum; j++){
                sm += Math.pow(point[j] - ave, 2);
            }
            double aa = sm / studentsNum;
            double result = Math.sqrt(aa);
            System.out.println(result);
        }
    }
} public class Main {
    static Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
        while (sc.hasNext()){
            int studentsNum = sc.nextInt();
            if (studentsNum == 0)
                break;
            double point[] = new double[studentsNum];
            double sum = 0;
            for (int i = 0; i < studentsNum; i++){
                point[i] = sc.nextInt();
                sum += point[i];
            }
            double ave = sum / studentsNum;
            double sm = 0;
            for (int j = 0; j < studentsNum; j++){
                sm += Math.pow(point[j] - ave, 2);
            }
            double aa = sm / studentsNum;
            double result = Math.sqrt(aa);
            System.out.println(result);
        }
    }
} Main

import java.util.Scanner;

public class Main {
    static Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
        while (sc.hasNext()){
            int studentsNum = sc.nextInt();
            if (studentsNum == 0)
                break;
            double point[] = new double[studentsNum];
            double sum = 0;
            for (int i = 0; i < studentsNum; i++){
                point[i] = sc.nextInt();
                sum += point[i];
            }
            double ave = sum / studentsNum;
            double sm = 0;
            for (int j = 0; j < studentsNum; j++){
                sm += Math.pow(point[j] - ave, 2);
            }
            double aa = sm / studentsNum;
            double result = Math.sqrt(aa);
            System.out.println(result);
        }
    }
}

