辗转相除法 

#include<iostream>
using namespace std;
int main()
{
	int m, n;
	cin >> m >> n;
	int a, b;
	if (m > n) {
		a = m;
		b = n;
	}
	else {
		a = n;
		b = m;
	}
	while (a != b) {
		a -= b;
		if (a < b) {
			int tmp = a;
			a = b;
			b = tmp;
		}
	}
	cout << a << " " << m*n/a << endl;
	return 0;
}