import java.util.Scanner;

public class Main {
    public static void main (String[] args)
    {
        try
        {
            Scanner sc = new Scanner(System.in);
            int i, n, sum;
            double avg, s2;
            double[] s = new double[10000];

            for (i = 0; true; i++)
            {
                n = sc.nextInt();
                if (n == 0) break;
                sum = 0;
                s2 = 0;
                int[] x = new int[n];
                for (int m = 0; m < n; m++)
                {
                    x[m] = sc.nextInt();
                    sum += x[m];
                }
                avg = (double) sum / n;

                for (int m = 0; m < n; m++)
                {
                    s2 += (double) (x[m] - avg) * (x[m] - avg);
                }
                s[i] = Math.sqrt(s2 / n);
            }
            sc.close();

            for (int m = 0; m < i; m++)
            {
                System.out.println(s[m]);
            }
        }
        catch (NumberFormatException e)
        {
            System.out.println(e);
        }
    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void main (String[] args)
    {
        try
        {
            Scanner sc = new Scanner(System.in);
            int i, n, sum;
            double avg, s2;
            double[] s = new double[10000];

            for (i = 0; true; i++)
            {
                n = sc.nextInt();
                if (n == 0) break;
                sum = 0;
                s2 = 0;
                int[] x = new int[n];
                for (int m = 0; m < n; m++)
                {
                    x[m] = sc.nextInt();
                    sum += x[m];
                }
                avg = (double) sum / n;

                for (int m = 0; m < n; m++)
                {
                    s2 += (double) (x[m] - avg) * (x[m] - avg);
                }
                s[i] = Math.sqrt(s2 / n);
            }
            sc.close();

            for (int m = 0; m < i; m++)
            {
                System.out.println(s[m]);
            }
        }
        catch (NumberFormatException e)
        {
            System.out.println(e);
        }
    }
} Main public static void main (String[] args)
    {
        try
        {
            Scanner sc = new Scanner(System.in);
            int i, n, sum;
            double avg, s2;
            double[] s = new double[10000];

            for (i = 0; true; i++)
            {
                n = sc.nextInt();
                if (n == 0) break;
                sum = 0;
                s2 = 0;
                int[] x = new int[n];
                for (int m = 0; m < n; m++)
                {
                    x[m] = sc.nextInt();
                    sum += x[m];
                }
                avg = (double) sum / n;

                for (int m = 0; m < n; m++)
                {
                    s2 += (double) (x[m] - avg) * (x[m] - avg);
                }
                s[i] = Math.sqrt(s2 / n);
            }
            sc.close();

            for (int m = 0; m < i; m++)
            {
                System.out.println(s[m]);
            }
        }
        catch (NumberFormatException e)
        {
            System.out.println(e);
        }
    } main {
        try
        {
            Scanner sc = new Scanner(System.in);
            int i, n, sum;
            double avg, s2;
            double[] s = new double[10000];

            for (i = 0; true; i++)
            {
                n = sc.nextInt();
                if (n == 0) break;
                sum = 0;
                s2 = 0;
                int[] x = new int[n];
                for (int m = 0; m < n; m++)
                {
                    x[m] = sc.nextInt();
                    sum += x[m];
                }
                avg = (double) sum / n;

                for (int m = 0; m < n; m++)
                {
                    s2 += (double) (x[m] - avg) * (x[m] - avg);
                }
                s[i] = Math.sqrt(s2 / n);
            }
            sc.close();

            for (int m = 0; m < i; m++)
            {
                System.out.println(s[m]);
            }
        }
        catch (NumberFormatException e)
        {
            System.out.println(e);
        }
    } try
        {
            Scanner sc = new Scanner(System.in);
            int i, n, sum;
            double avg, s2;
            double[] s = new double[10000];

            for (i = 0; true; i++)
            {
                n = sc.nextInt();
                if (n == 0) break;
                sum = 0;
                s2 = 0;
                int[] x = new int[n];
                for (int m = 0; m < n; m++)
                {
                    x[m] = sc.nextInt();
                    sum += x[m];
                }
                avg = (double) sum / n;

                for (int m = 0; m < n; m++)
                {
                    s2 += (double) (x[m] - avg) * (x[m] - avg);
                }
                s[i] = Math.sqrt(s2 / n);
            }
            sc.close();

            for (int m = 0; m < i; m++)
            {
                System.out.println(s[m]);
            }
        }
        catch (NumberFormatException e)
        {
            System.out.println(e);
        } catch (NumberFormatException e)
        {
            System.out.println(e);
        } NumberFormatException e {
            System.out.println(e);
        } System.out.println(e) System.out.println System.out System System.out e {
            Scanner sc = new Scanner(System.in);
            int i, n, sum;
            double avg, s2;
            double[] s = new double[10000];

            for (i = 0; true; i++)
            {
                n = sc.nextInt();
                if (n == 0) break;
                sum = 0;
                s2 = 0;
                int[] x = new int[n];
                for (int m = 0; m < n; m++)
                {
                    x[m] = sc.nextInt();
                    sum += x[m];
                }
                avg = (double) sum / n;

                for (int m = 0; m < n; m++)
                {
                    s2 += (double) (x[m] - avg) * (x[m] - avg);
                }
                s[i] = Math.sqrt(s2 / n);
            }
            sc.close();

            for (int m = 0; m < i; m++)
            {
                System.out.println(s[m]);
            }
        } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int i i n n sum; sum double avg avg s2; s2 double[] s = new double[10000]; s new double[10000] 10000 for (i = 0; true; i++)
            {
                n = sc.nextInt();
                if (n == 0) break;
                sum = 0;
                s2 = 0;
                int[] x = new int[n];
                for (int m = 0; m < n; m++)
                {
                    x[m] = sc.nextInt();
                    sum += x[m];
                }
                avg = (double) sum / n;

                for (int m = 0; m < n; m++)
                {
                    s2 += (double) (x[m] - avg) * (x[m] - avg);
                }
                s[i] = Math.sqrt(s2 / n);
            } i = 0; i = 0 i 0 true i++ i++ i {
                n = sc.nextInt();
                if (n == 0) break;
                sum = 0;
                s2 = 0;
                int[] x = new int[n];
                for (int m = 0; m < n; m++)
                {
                    x[m] = sc.nextInt();
                    sum += x[m];
                }
                avg = (double) sum / n;

                for (int m = 0; m < n; m++)
                {
                    s2 += (double) (x[m] - avg) * (x[m] - avg);
                }
                s[i] = Math.sqrt(s2 / n);
            } {
                n = sc.nextInt();
                if (n == 0) break;
                sum = 0;
                s2 = 0;
                int[] x = new int[n];
                for (int m = 0; m < n; m++)
                {
                    x[m] = sc.nextInt();
                    sum += x[m];
                }
                avg = (double) sum / n;

                for (int m = 0; m < n; m++)
                {
                    s2 += (double) (x[m] - avg) * (x[m] - avg);
                }
                s[i] = Math.sqrt(s2 / n);
            } n = sc.nextInt() n sc.nextInt() sc.nextInt sc if (n == 0) break; n == 0 n 0 break; sum = 0 sum 0 s2 = 0 s2 0 int[] x = new int[n]; x new int[n] n for (int m = 0; m < n; m++)
                {
                    x[m] = sc.nextInt();
                    sum += x[m];
                } int m = 0; int m = 0; m 0 m < n m n m++ m++ m {
                    x[m] = sc.nextInt();
                    sum += x[m];
                } {
                    x[m] = sc.nextInt();
                    sum += x[m];
                } x[m] = sc.nextInt() x[m] x m sc.nextInt() sc.nextInt sc sum += x[m] sum x[m] x m avg = (double) sum / n avg (double) sum / n (double) sum n for (int m = 0; m < n; m++)
                {
                    s2 += (double) (x[m] - avg) * (x[m] - avg);
                } int m = 0; int m = 0; m 0 m < n m n m++ m++ m {
                    s2 += (double) (x[m] - avg) * (x[m] - avg);
                } {
                    s2 += (double) (x[m] - avg) * (x[m] - avg);
                } s2 += (double) (x[m] - avg) * (x[m] - avg) s2 (double) (x[m] - avg) * (x[m] - avg) (double) (x[m] - avg) x[m] x m avg (x[m] - avg) x[m] x m avg s[i] = Math.sqrt(s2 / n) s[i] s i Math.sqrt(s2 / n) Math.sqrt Math s2 / n s2 n sc.close() sc.close sc for (int m = 0; m < i; m++)
            {
                System.out.println(s[m]);
            } int m = 0; int m = 0; m 0 m < i m i m++ m++ m {
                System.out.println(s[m]);
            } {
                System.out.println(s[m]);
            } System.out.println(s[m]) System.out.println System.out System System.out s[m] s m String[] args args public class Main {
    public static void main (String[] args)
    {
        try
        {
            Scanner sc = new Scanner(System.in);
            int i, n, sum;
            double avg, s2;
            double[] s = new double[10000];

            for (i = 0; true; i++)
            {
                n = sc.nextInt();
                if (n == 0) break;
                sum = 0;
                s2 = 0;
                int[] x = new int[n];
                for (int m = 0; m < n; m++)
                {
                    x[m] = sc.nextInt();
                    sum += x[m];
                }
                avg = (double) sum / n;

                for (int m = 0; m < n; m++)
                {
                    s2 += (double) (x[m] - avg) * (x[m] - avg);
                }
                s[i] = Math.sqrt(s2 / n);
            }
            sc.close();

            for (int m = 0; m < i; m++)
            {
                System.out.println(s[m]);
            }
        }
        catch (NumberFormatException e)
        {
            System.out.println(e);
        }
    }
} public class Main {
    public static void main (String[] args)
    {
        try
        {
            Scanner sc = new Scanner(System.in);
            int i, n, sum;
            double avg, s2;
            double[] s = new double[10000];

            for (i = 0; true; i++)
            {
                n = sc.nextInt();
                if (n == 0) break;
                sum = 0;
                s2 = 0;
                int[] x = new int[n];
                for (int m = 0; m < n; m++)
                {
                    x[m] = sc.nextInt();
                    sum += x[m];
                }
                avg = (double) sum / n;

                for (int m = 0; m < n; m++)
                {
                    s2 += (double) (x[m] - avg) * (x[m] - avg);
                }
                s[i] = Math.sqrt(s2 / n);
            }
            sc.close();

            for (int m = 0; m < i; m++)
            {
                System.out.println(s[m]);
            }
        }
        catch (NumberFormatException e)
        {
            System.out.println(e);
        }
    }
} Main
import java.util.Scanner;

public class Main {
    public static void main (String[] args)
    {
        try
        {
            Scanner sc = new Scanner(System.in);
            int i, n, sum;
            double avg, s2;
            double[] s = new double[10000];

            for (i = 0; true; i++)
            {
                n = sc.nextInt();
                if (n == 0) break;
                sum = 0;
                s2 = 0;
                int[] x = new int[n];
                for (int m = 0; m < n; m++)
                {
                    x[m] = sc.nextInt();
                    sum += x[m];
                }
                avg = (double) sum / n;

                for (int m = 0; m < n; m++)
                {
                    s2 += (double) (x[m] - avg) * (x[m] - avg);
                }
                s[i] = Math.sqrt(s2 / n);
            }
            sc.close();

            for (int m = 0; m < i; m++)
            {
                System.out.println(s[m]);
            }
        }
        catch (NumberFormatException e)
        {
            System.out.println(e);
        }
    }
}
