C :

#include<stdio.h>
int main()
{
	long a, b;
	long temp;
	scanf("%ld%ld", &a, &b);
	temp = a;
	a = b;
	b = temp;
	printf("%ld %ld", a, b);
	return 0;
}

C++ :

#include <cstdio>
//#include<cstdlib>
int main(){
  int a, b, t;
  scanf("%d%d", &a, &b);
  t = a;
  a = b;
  b = t;
  printf("%d %d\n", a, b);
  //system("pause");
  return 0;
}

Pascal :

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