import java.util.*;
 
class Main {
    public static void main(String[] args) {
    	
    	Scanner sc = new Scanner(System.in);
    	ArrayList<Double> sList = new ArrayList<>();
    	ArrayList<Double> devList = new ArrayList<>();
    	ArrayList<Double> sigmaList = new ArrayList<>();
    	
    	int n = 999;
    	double s;
    	double sum = 0;;
    	double avg;
    	double disp = 0;
    	double sigma;
    	int cnt = 0;
    	while(n != 0) {
    		n = sc.nextInt();
    		if(n == 0) {
    			break;
    		} else {
       			//ArrayList?????????
    			for(int i = 0; i < n; i++) {
    	    		sList.add(0.0);
    	    		devList.add(0.0);
    	    	}
    			//???????????\???
    	    	for(int i = 0; i < n; i++) {
    	    		s = sc.nextDouble();
    	    		sList.set(i, s);
    	    	}
    	    	//????¨?
    	    	for(int i = 0; i < n; i++) {
    	    		sum = sList.get(i) + sum;
    	    	}
    	    	//??????
    	    	avg = sum / n;
    	    	//??????
    	    	for(int i = 0; i < n; i++) {
    	    		devList.set(i, Math.abs(sList.get(i) - avg));
    	    	}
    	    	//?????£
    	    	for(int i = 0; i < n; i++) {
    	    		disp = devList.get(i) * devList.get(i) + disp;
    	    	}
    	    	disp = disp / n;
    	    	//?¨??????????
    	    	sigma = Math.sqrt(disp);
    	    	sigmaList.add(sigma);
    	    	cnt++;
    		}
    		sum = 0;
    		avg = 0;
    		disp = 0;
    		sigma = 0;
    	}
    	for(int i = 0; i < cnt; i++) {
    		System.out.println(sigmaList.get(i));
    	}
    }
} import java.util.*; util.* java class Main {
    public static void main(String[] args) {
    	
    	Scanner sc = new Scanner(System.in);
    	ArrayList<Double> sList = new ArrayList<>();
    	ArrayList<Double> devList = new ArrayList<>();
    	ArrayList<Double> sigmaList = new ArrayList<>();
    	
    	int n = 999;
    	double s;
    	double sum = 0;;
    	double avg;
    	double disp = 0;
    	double sigma;
    	int cnt = 0;
    	while(n != 0) {
    		n = sc.nextInt();
    		if(n == 0) {
    			break;
    		} else {
       			//ArrayList?????????
    			for(int i = 0; i < n; i++) {
    	    		sList.add(0.0);
    	    		devList.add(0.0);
    	    	}
    			//???????????\???
    	    	for(int i = 0; i < n; i++) {
    	    		s = sc.nextDouble();
    	    		sList.set(i, s);
    	    	}
    	    	//????¨?
    	    	for(int i = 0; i < n; i++) {
    	    		sum = sList.get(i) + sum;
    	    	}
    	    	//??????
    	    	avg = sum / n;
    	    	//??????
    	    	for(int i = 0; i < n; i++) {
    	    		devList.set(i, Math.abs(sList.get(i) - avg));
    	    	}
    	    	//?????£
    	    	for(int i = 0; i < n; i++) {
    	    		disp = devList.get(i) * devList.get(i) + disp;
    	    	}
    	    	disp = disp / n;
    	    	//?¨??????????
    	    	sigma = Math.sqrt(disp);
    	    	sigmaList.add(sigma);
    	    	cnt++;
    		}
    		sum = 0;
    		avg = 0;
    		disp = 0;
    		sigma = 0;
    	}
    	for(int i = 0; i < cnt; i++) {
    		System.out.println(sigmaList.get(i));
    	}
    }
} Main public static void main(String[] args) {
    	
    	Scanner sc = new Scanner(System.in);
    	ArrayList<Double> sList = new ArrayList<>();
    	ArrayList<Double> devList = new ArrayList<>();
    	ArrayList<Double> sigmaList = new ArrayList<>();
    	
    	int n = 999;
    	double s;
    	double sum = 0;;
    	double avg;
    	double disp = 0;
    	double sigma;
    	int cnt = 0;
    	while(n != 0) {
    		n = sc.nextInt();
    		if(n == 0) {
    			break;
    		} else {
       			//ArrayList?????????
    			for(int i = 0; i < n; i++) {
    	    		sList.add(0.0);
    	    		devList.add(0.0);
    	    	}
    			//???????????\???
    	    	for(int i = 0; i < n; i++) {
    	    		s = sc.nextDouble();
    	    		sList.set(i, s);
    	    	}
    	    	//????¨?
    	    	for(int i = 0; i < n; i++) {
    	    		sum = sList.get(i) + sum;
    	    	}
    	    	//??????
    	    	avg = sum / n;
    	    	//??????
    	    	for(int i = 0; i < n; i++) {
    	    		devList.set(i, Math.abs(sList.get(i) - avg));
    	    	}
    	    	//?????£
    	    	for(int i = 0; i < n; i++) {
    	    		disp = devList.get(i) * devList.get(i) + disp;
    	    	}
    	    	disp = disp / n;
    	    	//?¨??????????
    	    	sigma = Math.sqrt(disp);
    	    	sigmaList.add(sigma);
    	    	cnt++;
    		}
    		sum = 0;
    		avg = 0;
    		disp = 0;
    		sigma = 0;
    	}
    	for(int i = 0; i < cnt; i++) {
    		System.out.println(sigmaList.get(i));
    	}
    } main {
    	
    	Scanner sc = new Scanner(System.in);
    	ArrayList<Double> sList = new ArrayList<>();
    	ArrayList<Double> devList = new ArrayList<>();
    	ArrayList<Double> sigmaList = new ArrayList<>();
    	
    	int n = 999;
    	double s;
    	double sum = 0;;
    	double avg;
    	double disp = 0;
    	double sigma;
    	int cnt = 0;
    	while(n != 0) {
    		n = sc.nextInt();
    		if(n == 0) {
    			break;
    		} else {
       			//ArrayList?????????
    			for(int i = 0; i < n; i++) {
    	    		sList.add(0.0);
    	    		devList.add(0.0);
    	    	}
    			//???????????\???
    	    	for(int i = 0; i < n; i++) {
    	    		s = sc.nextDouble();
    	    		sList.set(i, s);
    	    	}
    	    	//????¨?
    	    	for(int i = 0; i < n; i++) {
    	    		sum = sList.get(i) + sum;
    	    	}
    	    	//??????
    	    	avg = sum / n;
    	    	//??????
    	    	for(int i = 0; i < n; i++) {
    	    		devList.set(i, Math.abs(sList.get(i) - avg));
    	    	}
    	    	//?????£
    	    	for(int i = 0; i < n; i++) {
    	    		disp = devList.get(i) * devList.get(i) + disp;
    	    	}
    	    	disp = disp / n;
    	    	//?¨??????????
    	    	sigma = Math.sqrt(disp);
    	    	sigmaList.add(sigma);
    	    	cnt++;
    		}
    		sum = 0;
    		avg = 0;
    		disp = 0;
    		sigma = 0;
    	}
    	for(int i = 0; i < cnt; i++) {
    		System.out.println(sigmaList.get(i));
    	}
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) ArrayList<Double> sList = new ArrayList<>(); sList new ArrayList<>() ArrayList<Double> devList = new ArrayList<>(); devList new ArrayList<>() ArrayList<Double> sigmaList = new ArrayList<>(); sigmaList new ArrayList<>() int n = 999; n 999 double s; s double sum = 0; sum 0 double avg; avg double disp = 0; disp 0 double sigma; sigma int cnt = 0; cnt 0 while(n != 0) {
    		n = sc.nextInt();
    		if(n == 0) {
    			break;
    		} else {
       			//ArrayList?????????
    			for(int i = 0; i < n; i++) {
    	    		sList.add(0.0);
    	    		devList.add(0.0);
    	    	}
    			//???????????\???
    	    	for(int i = 0; i < n; i++) {
    	    		s = sc.nextDouble();
    	    		sList.set(i, s);
    	    	}
    	    	//????¨?
    	    	for(int i = 0; i < n; i++) {
    	    		sum = sList.get(i) + sum;
    	    	}
    	    	//??????
    	    	avg = sum / n;
    	    	//??????
    	    	for(int i = 0; i < n; i++) {
    	    		devList.set(i, Math.abs(sList.get(i) - avg));
    	    	}
    	    	//?????£
    	    	for(int i = 0; i < n; i++) {
    	    		disp = devList.get(i) * devList.get(i) + disp;
    	    	}
    	    	disp = disp / n;
    	    	//?¨??????????
    	    	sigma = Math.sqrt(disp);
    	    	sigmaList.add(sigma);
    	    	cnt++;
    		}
    		sum = 0;
    		avg = 0;
    		disp = 0;
    		sigma = 0;
    	} n != 0 n 0 {
    		n = sc.nextInt();
    		if(n == 0) {
    			break;
    		} else {
       			//ArrayList?????????
    			for(int i = 0; i < n; i++) {
    	    		sList.add(0.0);
    	    		devList.add(0.0);
    	    	}
    			//???????????\???
    	    	for(int i = 0; i < n; i++) {
    	    		s = sc.nextDouble();
    	    		sList.set(i, s);
    	    	}
    	    	//????¨?
    	    	for(int i = 0; i < n; i++) {
    	    		sum = sList.get(i) + sum;
    	    	}
    	    	//??????
    	    	avg = sum / n;
    	    	//??????
    	    	for(int i = 0; i < n; i++) {
    	    		devList.set(i, Math.abs(sList.get(i) - avg));
    	    	}
    	    	//?????£
    	    	for(int i = 0; i < n; i++) {
    	    		disp = devList.get(i) * devList.get(i) + disp;
    	    	}
    	    	disp = disp / n;
    	    	//?¨??????????
    	    	sigma = Math.sqrt(disp);
    	    	sigmaList.add(sigma);
    	    	cnt++;
    		}
    		sum = 0;
    		avg = 0;
    		disp = 0;
    		sigma = 0;
    	} n = sc.nextInt() n sc.nextInt() sc.nextInt sc if(n == 0) {
    			break;
    		} else {
       			//ArrayList?????????
    			for(int i = 0; i < n; i++) {
    	    		sList.add(0.0);
    	    		devList.add(0.0);
    	    	}
    			//???????????\???
    	    	for(int i = 0; i < n; i++) {
    	    		s = sc.nextDouble();
    	    		sList.set(i, s);
    	    	}
    	    	//????¨?
    	    	for(int i = 0; i < n; i++) {
    	    		sum = sList.get(i) + sum;
    	    	}
    	    	//??????
    	    	avg = sum / n;
    	    	//??????
    	    	for(int i = 0; i < n; i++) {
    	    		devList.set(i, Math.abs(sList.get(i) - avg));
    	    	}
    	    	//?????£
    	    	for(int i = 0; i < n; i++) {
    	    		disp = devList.get(i) * devList.get(i) + disp;
    	    	}
    	    	disp = disp / n;
    	    	//?¨??????????
    	    	sigma = Math.sqrt(disp);
    	    	sigmaList.add(sigma);
    	    	cnt++;
    		} n == 0 n 0 {
    			break;
    		} break; {
       			//ArrayList?????????
    			for(int i = 0; i < n; i++) {
    	    		sList.add(0.0);
    	    		devList.add(0.0);
    	    	}
    			//???????????\???
    	    	for(int i = 0; i < n; i++) {
    	    		s = sc.nextDouble();
    	    		sList.set(i, s);
    	    	}
    	    	//????¨?
    	    	for(int i = 0; i < n; i++) {
    	    		sum = sList.get(i) + sum;
    	    	}
    	    	//??????
    	    	avg = sum / n;
    	    	//??????
    	    	for(int i = 0; i < n; i++) {
    	    		devList.set(i, Math.abs(sList.get(i) - avg));
    	    	}
    	    	//?????£
    	    	for(int i = 0; i < n; i++) {
    	    		disp = devList.get(i) * devList.get(i) + disp;
    	    	}
    	    	disp = disp / n;
    	    	//?¨??????????
    	    	sigma = Math.sqrt(disp);
    	    	sigmaList.add(sigma);
    	    	cnt++;
    		} for(int i = 0; i < n; i++) {
    	    		sList.add(0.0);
    	    		devList.add(0.0);
    	    	} int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
    	    		sList.add(0.0);
    	    		devList.add(0.0);
    	    	} {
    	    		sList.add(0.0);
    	    		devList.add(0.0);
    	    	} sList.add(0.0) sList.add sList 0.0 devList.add(0.0) devList.add devList 0.0 for(int i = 0; i < n; i++) {
    	    		s = sc.nextDouble();
    	    		sList.set(i, s);
    	    	} int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
    	    		s = sc.nextDouble();
    	    		sList.set(i, s);
    	    	} {
    	    		s = sc.nextDouble();
    	    		sList.set(i, s);
    	    	} s = sc.nextDouble() s sc.nextDouble() sc.nextDouble sc sList.set(i, s) sList.set sList i s for(int i = 0; i < n; i++) {
    	    		sum = sList.get(i) + sum;
    	    	} int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
    	    		sum = sList.get(i) + sum;
    	    	} {
    	    		sum = sList.get(i) + sum;
    	    	} sum = sList.get(i) + sum sum sList.get(i) + sum sList.get(i) sList.get sList i sum avg = sum / n avg sum / n sum n for(int i = 0; i < n; i++) {
    	    		devList.set(i, Math.abs(sList.get(i) - avg));
    	    	} int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
    	    		devList.set(i, Math.abs(sList.get(i) - avg));
    	    	} {
    	    		devList.set(i, Math.abs(sList.get(i) - avg));
    	    	} devList.set(i, Math.abs(sList.get(i) - avg)) devList.set devList i Math.abs(sList.get(i) - avg) Math.abs Math sList.get(i) - avg sList.get(i) sList.get sList i avg for(int i = 0; i < n; i++) {
    	    		disp = devList.get(i) * devList.get(i) + disp;
    	    	} int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
    	    		disp = devList.get(i) * devList.get(i) + disp;
    	    	} {
    	    		disp = devList.get(i) * devList.get(i) + disp;
    	    	} disp = devList.get(i) * devList.get(i) + disp disp devList.get(i) * devList.get(i) + disp devList.get(i) * devList.get(i) devList.get(i) devList.get devList i devList.get(i) devList.get devList i disp disp = disp / n disp disp / n disp n sigma = Math.sqrt(disp) sigma Math.sqrt(disp) Math.sqrt Math disp sigmaList.add(sigma) sigmaList.add sigmaList sigma cnt++ cnt sum = 0 sum 0 avg = 0 avg 0 disp = 0 disp 0 sigma = 0 sigma 0 for(int i = 0; i < cnt; i++) {
    		System.out.println(sigmaList.get(i));
    	} int i = 0; int i = 0; i 0 i < cnt i cnt i++ i++ i {
    		System.out.println(sigmaList.get(i));
    	} {
    		System.out.println(sigmaList.get(i));
    	} System.out.println(sigmaList.get(i)) System.out.println System.out System System.out sigmaList.get(i) sigmaList.get sigmaList i String[] args args
import java.util.*;
 
class Main {
    public static void main(String[] args) {
    	
    	Scanner sc = new Scanner(System.in);
    	ArrayList<Double> sList = new ArrayList<>();
    	ArrayList<Double> devList = new ArrayList<>();
    	ArrayList<Double> sigmaList = new ArrayList<>();
    	
    	int n = 999;
    	double s;
    	double sum = 0;;
    	double avg;
    	double disp = 0;
    	double sigma;
    	int cnt = 0;
    	while(n != 0) {
    		n = sc.nextInt();
    		if(n == 0) {
    			break;
    		} else {
       			//ArrayList?????????
    			for(int i = 0; i < n; i++) {
    	    		sList.add(0.0);
    	    		devList.add(0.0);
    	    	}
    			//???????????\???
    	    	for(int i = 0; i < n; i++) {
    	    		s = sc.nextDouble();
    	    		sList.set(i, s);
    	    	}
    	    	//????¨?
    	    	for(int i = 0; i < n; i++) {
    	    		sum = sList.get(i) + sum;
    	    	}
    	    	//??????
    	    	avg = sum / n;
    	    	//??????
    	    	for(int i = 0; i < n; i++) {
    	    		devList.set(i, Math.abs(sList.get(i) - avg));
    	    	}
    	    	//?????£
    	    	for(int i = 0; i < n; i++) {
    	    		disp = devList.get(i) * devList.get(i) + disp;
    	    	}
    	    	disp = disp / n;
    	    	//?¨??????????
    	    	sigma = Math.sqrt(disp);
    	    	sigmaList.add(sigma);
    	    	cnt++;
    		}
    		sum = 0;
    		avg = 0;
    		disp = 0;
    		sigma = 0;
    	}
    	for(int i = 0; i < cnt; i++) {
    		System.out.println(sigmaList.get(i));
    	}
    }
}