C++ :

#include<iostream>
#include<cstdio>
using namespace std;
int c,d;
void swap(int &c,int &d);
void swap(int &c,int &d)
{
	int t;
	t=c;
	c=d;
	d=t;
}
int main()
{
	int a,b;
	cin>>a>>b;
	swap(a,b);
	cout<<a<<' '<<b<<endl;
	return 0;
}

Pascal :

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