
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        try (Scanner sc = new Scanner(System.in)) {
            while (true) {
                int n = sc.nextInt();
                int sum = 0;
                if (n == 0) { break; }
                int[] scores = new int[n];
                for (int i = 0; i < scores.length; i++) {
                    scores[i] = sc.nextInt();
                }
                double average = 0, variance = 0, y = 0;
                for (int i = 0; i < scores.length; i++) {
                    sum = sum + scores[i];
                }
                average = (double)sum / n;
                for (int i = 0; i < scores.length; i++) {
                    double x = Math.pow((scores[i] - average), 2);
                    y = x + y;
                }
                variance = y / n;
                System.out.println(Math.sqrt(variance));
            }
        }
    }
}
 import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        try (Scanner sc = new Scanner(System.in)) {
            while (true) {
                int n = sc.nextInt();
                int sum = 0;
                if (n == 0) { break; }
                int[] scores = new int[n];
                for (int i = 0; i < scores.length; i++) {
                    scores[i] = sc.nextInt();
                }
                double average = 0, variance = 0, y = 0;
                for (int i = 0; i < scores.length; i++) {
                    sum = sum + scores[i];
                }
                average = (double)sum / n;
                for (int i = 0; i < scores.length; i++) {
                    double x = Math.pow((scores[i] - average), 2);
                    y = x + y;
                }
                variance = y / n;
                System.out.println(Math.sqrt(variance));
            }
        }
    }
} Main public static void main(String[] args) {
        try (Scanner sc = new Scanner(System.in)) {
            while (true) {
                int n = sc.nextInt();
                int sum = 0;
                if (n == 0) { break; }
                int[] scores = new int[n];
                for (int i = 0; i < scores.length; i++) {
                    scores[i] = sc.nextInt();
                }
                double average = 0, variance = 0, y = 0;
                for (int i = 0; i < scores.length; i++) {
                    sum = sum + scores[i];
                }
                average = (double)sum / n;
                for (int i = 0; i < scores.length; i++) {
                    double x = Math.pow((scores[i] - average), 2);
                    y = x + y;
                }
                variance = y / n;
                System.out.println(Math.sqrt(variance));
            }
        }
    } main {
        try (Scanner sc = new Scanner(System.in)) {
            while (true) {
                int n = sc.nextInt();
                int sum = 0;
                if (n == 0) { break; }
                int[] scores = new int[n];
                for (int i = 0; i < scores.length; i++) {
                    scores[i] = sc.nextInt();
                }
                double average = 0, variance = 0, y = 0;
                for (int i = 0; i < scores.length; i++) {
                    sum = sum + scores[i];
                }
                average = (double)sum / n;
                for (int i = 0; i < scores.length; i++) {
                    double x = Math.pow((scores[i] - average), 2);
                    y = x + y;
                }
                variance = y / n;
                System.out.println(Math.sqrt(variance));
            }
        }
    } try (Scanner sc = new Scanner(System.in)) {
            while (true) {
                int n = sc.nextInt();
                int sum = 0;
                if (n == 0) { break; }
                int[] scores = new int[n];
                for (int i = 0; i < scores.length; i++) {
                    scores[i] = sc.nextInt();
                }
                double average = 0, variance = 0, y = 0;
                for (int i = 0; i < scores.length; i++) {
                    sum = sum + scores[i];
                }
                average = (double)sum / n;
                for (int i = 0; i < scores.length; i++) {
                    double x = Math.pow((scores[i] - average), 2);
                    y = x + y;
                }
                variance = y / n;
                System.out.println(Math.sqrt(variance));
            }
        } {
            while (true) {
                int n = sc.nextInt();
                int sum = 0;
                if (n == 0) { break; }
                int[] scores = new int[n];
                for (int i = 0; i < scores.length; i++) {
                    scores[i] = sc.nextInt();
                }
                double average = 0, variance = 0, y = 0;
                for (int i = 0; i < scores.length; i++) {
                    sum = sum + scores[i];
                }
                average = (double)sum / n;
                for (int i = 0; i < scores.length; i++) {
                    double x = Math.pow((scores[i] - average), 2);
                    y = x + y;
                }
                variance = y / n;
                System.out.println(Math.sqrt(variance));
            }
        } Scanner sc = new Scanner(System.in) Scanner sc = new Scanner(System.in) new Scanner(System.in) while (true) {
                int n = sc.nextInt();
                int sum = 0;
                if (n == 0) { break; }
                int[] scores = new int[n];
                for (int i = 0; i < scores.length; i++) {
                    scores[i] = sc.nextInt();
                }
                double average = 0, variance = 0, y = 0;
                for (int i = 0; i < scores.length; i++) {
                    sum = sum + scores[i];
                }
                average = (double)sum / n;
                for (int i = 0; i < scores.length; i++) {
                    double x = Math.pow((scores[i] - average), 2);
                    y = x + y;
                }
                variance = y / n;
                System.out.println(Math.sqrt(variance));
            } true {
                int n = sc.nextInt();
                int sum = 0;
                if (n == 0) { break; }
                int[] scores = new int[n];
                for (int i = 0; i < scores.length; i++) {
                    scores[i] = sc.nextInt();
                }
                double average = 0, variance = 0, y = 0;
                for (int i = 0; i < scores.length; i++) {
                    sum = sum + scores[i];
                }
                average = (double)sum / n;
                for (int i = 0; i < scores.length; i++) {
                    double x = Math.pow((scores[i] - average), 2);
                    y = x + y;
                }
                variance = y / n;
                System.out.println(Math.sqrt(variance));
            } int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc int sum = 0; sum 0 if (n == 0) { break; } n == 0 n 0 { break; } break; int[] scores = new int[n]; scores new int[n] n for (int i = 0; i < scores.length; i++) {
                    scores[i] = sc.nextInt();
                } int i = 0; int i = 0; i 0 i < scores.length i scores.length scores scores.length i++ i++ i {
                    scores[i] = sc.nextInt();
                } {
                    scores[i] = sc.nextInt();
                } scores[i] = sc.nextInt() scores[i] scores i sc.nextInt() sc.nextInt sc double average = 0 average 0 variance = 0 variance 0 y = 0; y 0 for (int i = 0; i < scores.length; i++) {
                    sum = sum + scores[i];
                } int i = 0; int i = 0; i 0 i < scores.length i scores.length scores scores.length i++ i++ i {
                    sum = sum + scores[i];
                } {
                    sum = sum + scores[i];
                } sum = sum + scores[i] sum sum + scores[i] sum scores[i] scores i average = (double)sum / n average (double)sum / n (double)sum n for (int i = 0; i < scores.length; i++) {
                    double x = Math.pow((scores[i] - average), 2);
                    y = x + y;
                } int i = 0; int i = 0; i 0 i < scores.length i scores.length scores scores.length i++ i++ i {
                    double x = Math.pow((scores[i] - average), 2);
                    y = x + y;
                } {
                    double x = Math.pow((scores[i] - average), 2);
                    y = x + y;
                } double x = Math.pow((scores[i] - average), 2); x Math.pow((scores[i] - average), 2) Math.pow Math (scores[i] - average) scores[i] scores i average 2 y = x + y y x + y x y variance = y / n variance y / n y n System.out.println(Math.sqrt(variance)) System.out.println System.out System System.out Math.sqrt(variance) Math.sqrt Math variance String[] args args public class Main {
    public static void main(String[] args) {
        try (Scanner sc = new Scanner(System.in)) {
            while (true) {
                int n = sc.nextInt();
                int sum = 0;
                if (n == 0) { break; }
                int[] scores = new int[n];
                for (int i = 0; i < scores.length; i++) {
                    scores[i] = sc.nextInt();
                }
                double average = 0, variance = 0, y = 0;
                for (int i = 0; i < scores.length; i++) {
                    sum = sum + scores[i];
                }
                average = (double)sum / n;
                for (int i = 0; i < scores.length; i++) {
                    double x = Math.pow((scores[i] - average), 2);
                    y = x + y;
                }
                variance = y / n;
                System.out.println(Math.sqrt(variance));
            }
        }
    }
} public class Main {
    public static void main(String[] args) {
        try (Scanner sc = new Scanner(System.in)) {
            while (true) {
                int n = sc.nextInt();
                int sum = 0;
                if (n == 0) { break; }
                int[] scores = new int[n];
                for (int i = 0; i < scores.length; i++) {
                    scores[i] = sc.nextInt();
                }
                double average = 0, variance = 0, y = 0;
                for (int i = 0; i < scores.length; i++) {
                    sum = sum + scores[i];
                }
                average = (double)sum / n;
                for (int i = 0; i < scores.length; i++) {
                    double x = Math.pow((scores[i] - average), 2);
                    y = x + y;
                }
                variance = y / n;
                System.out.println(Math.sqrt(variance));
            }
        }
    }
} Main

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        try (Scanner sc = new Scanner(System.in)) {
            while (true) {
                int n = sc.nextInt();
                int sum = 0;
                if (n == 0) { break; }
                int[] scores = new int[n];
                for (int i = 0; i < scores.length; i++) {
                    scores[i] = sc.nextInt();
                }
                double average = 0, variance = 0, y = 0;
                for (int i = 0; i < scores.length; i++) {
                    sum = sum + scores[i];
                }
                average = (double)sum / n;
                for (int i = 0; i < scores.length; i++) {
                    double x = Math.pow((scores[i] - average), 2);
                    y = x + y;
                }
                variance = y / n;
                System.out.println(Math.sqrt(variance));
            }
        }
    }
}

