import java.util.Arrays;
import java.util.Scanner;
public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int[] a = new int[2];
		while(true) {
			for(int i = 0; i<2; i++) {
				 a[i] = sc.nextInt();
			}
		  Arrays.sort(a);

		 if(a[0]==0 && a[1] ==0)break;
		 System.out.println(a[0] +" " + a[1]);

		}


    }

} import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int[] a = new int[2];
		while(true) {
			for(int i = 0; i<2; i++) {
				 a[i] = sc.nextInt();
			}
		  Arrays.sort(a);

		 if(a[0]==0 && a[1] ==0)break;
		 System.out.println(a[0] +" " + a[1]);

		}


    }

} Main public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int[] a = new int[2];
		while(true) {
			for(int i = 0; i<2; i++) {
				 a[i] = sc.nextInt();
			}
		  Arrays.sort(a);

		 if(a[0]==0 && a[1] ==0)break;
		 System.out.println(a[0] +" " + a[1]);

		}


    } main {

		Scanner sc = new Scanner(System.in);
		int[] a = new int[2];
		while(true) {
			for(int i = 0; i<2; i++) {
				 a[i] = sc.nextInt();
			}
		  Arrays.sort(a);

		 if(a[0]==0 && a[1] ==0)break;
		 System.out.println(a[0] +" " + a[1]);

		}


    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int[] a = new int[2]; a new int[2] 2 while(true) {
			for(int i = 0; i<2; i++) {
				 a[i] = sc.nextInt();
			}
		  Arrays.sort(a);

		 if(a[0]==0 && a[1] ==0)break;
		 System.out.println(a[0] +" " + a[1]);

		} true {
			for(int i = 0; i<2; i++) {
				 a[i] = sc.nextInt();
			}
		  Arrays.sort(a);

		 if(a[0]==0 && a[1] ==0)break;
		 System.out.println(a[0] +" " + a[1]);

		} for(int i = 0; i<2; i++) {
				 a[i] = sc.nextInt();
			} int i = 0; int i = 0; i 0 i<2 i 2 i++ i++ i {
				 a[i] = sc.nextInt();
			} {
				 a[i] = sc.nextInt();
			} a[i] = sc.nextInt() a[i] a i sc.nextInt() sc.nextInt sc Arrays.sort(a) Arrays.sort Arrays a if(a[0]==0 && a[1] ==0)break; a[0]==0 && a[1] ==0 a[0]==0 a[0] a 0 0 a[1] ==0 a[1] a 1 0 break; System.out.println(a[0] +" " + a[1]) System.out.println System.out System System.out a[0] +" " + a[1] a[0] +" " + a[1] a[0] a 0 " " a[1] a 1 String[] args args public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int[] a = new int[2];
		while(true) {
			for(int i = 0; i<2; i++) {
				 a[i] = sc.nextInt();
			}
		  Arrays.sort(a);

		 if(a[0]==0 && a[1] ==0)break;
		 System.out.println(a[0] +" " + a[1]);

		}


    }

} public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int[] a = new int[2];
		while(true) {
			for(int i = 0; i<2; i++) {
				 a[i] = sc.nextInt();
			}
		  Arrays.sort(a);

		 if(a[0]==0 && a[1] ==0)break;
		 System.out.println(a[0] +" " + a[1]);

		}


    }

} Main
import java.util.Arrays;
import java.util.Scanner;
public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int[] a = new int[2];
		while(true) {
			for(int i = 0; i<2; i++) {
				 a[i] = sc.nextInt();
			}
		  Arrays.sort(a);

		 if(a[0]==0 && a[1] ==0)break;
		 System.out.println(a[0] +" " + a[1]);

		}


    }

}
