C :

#include<stdio.h>
#define exchange(x,y)  printf("%d %d\n",y,x)

int main()
{
	int x,y;
	scanf("%d%d",&x,&y);
	exchange(x,y);
	return 0;
}

C++ :

#include <stdio.h>
#define swap(a, b) \
	do { \
		__typeof(a) temp = a; \
		a = b; \
		b = temp; \
	} while (0)
int main() {
	int a, b;
	scanf("%d%d", &a, &b);
	swap(a, b);
	printf("%d %d\n", a, b);
	return 0;
}

Pascal :

var
  a,b:longint;
begin
  readln(a,b);
  writeln(b,' ',a);
end.

Java :

import java.util.Scanner;

public class Main {
   private static Scanner s = new Scanner(System.in) ;
   
   public static void main(String[] args) {
     int a = s.nextInt() ;
     int b = s.nextInt() ;
     int temp = 0 ;
     if(a<b){
    	 temp = a ;
    	 a = b ;
    	 b = temp ;
     }
     
     System.out.println(a+" "+b);
   }
}