Go: package main

import "fmt"

func gcd(x, y int64) int64 {
	for y != 0 {
		r := x % y
		x = y
		y = r
	}
	return x
}

func lcm(x, y int64) int64 {
	return x / gcd(x, y) * y
}

func main() {
	for {
		var a, b int64

		fmt.Scanf("%d %d", &a, &b)

		if a == 0 && b == 0 {
			break
		}

		fmt.Printf("%d %d\n", gcd(a, b), lcm(a, b))
	}
}

C++: #include <iostream>
using namespace std;
int a1,a2;
int gcd,lcm;

int GCD(int a,int b){
    int i = 2;
    int minimum = min(a,b);
    if (minimum == 0){
        i = 0;
    }
    else if (minimum == 1){
        i = 1;
    }
    else {
        for (; i <= minimum; i++) {
            if (a % i == 0 && b % i == 0) {
                break;
            } else if (i == minimum) {
                i = 1;
                break;
            }
        }
    }
    return i;
}

int main(){
    while(cin >> a1 >> a2) {
        gcd = GCD(a1,a2);
        if (gcd == 0){
            lcm = 0;
        }
        else{
            lcm = a1*a2/gcd;
        }
        cout << gcd << " " << lcm << endl;
    }
}

C++: //
//  main.cpp
//  CppTest
//
//  Created by Ryu on 2017/02/08.
//  Copyright ?? 2017??´ Ryu. All rights reserved.
//

#include <iostream>
#include <algorithm>
#include <cstdio>
#include <cmath>
using namespace std;

long gcd(long x, long y){
    if (x > y) {
        if(x % y == 0){
            return y;
        }else{
            return gcd(y, x % y);
        }
    }else{
        if (y % x == 0) {
            return x;
        }else{
            return gcd(x, y % x);
        }
    }
}

int main(int argc, const char * argv[]) {
    // insert code here...
    cin.tie(0);
    ios::sync_with_stdio(false);
    
    long a[50], b[50], g[50], l[50];
    int n = 0;
    while (cin >> a[n] >> b[n]){
        g[n] = gcd(a[n], b[n]);
        l[n] = a[n] * b[n] / g[n];
        //printf("d: %f, x: %.4f, y: %.4f\n", d, x[n], y[n]);
        n++;
    }
    
    
    for(int i = 0; i < n; i++){
        printf("%ld %ld\n", g[i], l[i]);
    }
    
    
    return 0;
}

C++: #include <algorithm>
#include <iostream>
using namespace std;
 
int main() {
    long long int a, b;
    while (cin >> a >> b) {
    cout << a * b /(a/__gcd(a,b)*b)<< " " <<a/__gcd(a,b)*b<< endl;
  }
}

C++: #include <iostream>
using namespace std;

typedef long long lli;

lli gcd(lli a, lli b) {
  return b == 0 ? a : gcd(b, a%b);
}

lli lcm(lli a, lli b) {
  return a*b/gcd(a,b);
}

int main() {
  lli a, b;

  while(cin >> a >> b) {
    cout << gcd(a, b) << " " << lcm(a, b) << endl;
  }
  return 0;
}

C++: #include<iostream>
using namespace std;

double gcd(double m,double n);
double lcm(double m,double n);

int main(){
	int i;
	double a,b;
	double z[10] ={0} ;
	double y[10] = {0} ;


	for(i=0;i<4;i+=2){
		while(1){
			cin >> a >> b ;
			z[i] = a ;
			z[i+1] = b ;

			if((z[i] <= 200000000) && (z[i] > 0 )){
				if((z[i+1] <= 2000000000) && (z[i+1] > 0)) break;
			}
		}


	}

	y[0] = gcd(z[0],z[1]) ;
	y[1] = lcm(z[0],z[1]) ;
	y[2] = gcd(z[2],z[3]) ;
	y[3] = lcm(z[2],z[3]) ;

	cout << y[0] << " "<< y[1] << "\n" ;
	cout << y[2] << " " << y[3] << endl ;
	return 0;
}

	double gcd( double m, double n )
{
	// 引数に０がある場合は０を返す
	if ( ( 0 == m ) || ( 0 == n ) )
		return 0;
	
	// ユークリッドの方法
	while( m != n )
	{
		if ( m > n ) m = m - n;
		else         n = n - m;
	}
	return m;
}

double lcm( double m, double n )
{
	// 引数に０がある場合は０を返す
	if ( ( 0 == m ) || ( 0 == n ) )
		return 0;
	
	return ((m / gcd(m, n)) * n); // lcm = m * n / gcd(m,n)
}

C++: #include<iostream>

int gcd(int a, int b){
  int k;
  if(b>a){
    k=b;
    b=a;
    a=k;
  }
  while(k!=0){
    k = a % b;
    a = b;
    b = k;
  }
  return a;
}

int main(){
  int a, b;

  while(std::cin >> a >> b){
    std::cout << (a*b)/gcd(a,b) << " " << gcd(a,b) << std::endl;
  }
}

C++: //#define _GRIBCXX_DEBUG
#include <algorithm>
#include <cctype>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <functional>
#include <iostream>
#include <iomanip>
#include <list>
#include <map>
#include <memory>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <utility>
#include <vector>
using namespace std;


// ?????¬???????????¬??????
#pragma region MACRO
#define P(x) cout << (x) << endl
#define p(x) cout << (x)
#define PED cout << "\n"
#define rep(i,n) for(int i=0; i<(int)n; ++i)
#define REP(i,x,n) for(int i=x; i<(int)n; ++i)
#define repi(i,n) for(int i=0; i<=(int)n; ++i)
#define REPI(i,x,n) for(int i=x; i<=(int)n; ++i)
#define ILP while(true)
#define FOR(i,c) for(__typeof((c).begin())!=(c).begin(); i!=(c).end(); ++i)
#define ALL(c) (c).begin(), (c).end()
#define mp make_pair
#pragma endregion

#pragma region TYPE_DEF
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<string, string> pss;
typedef pair<string, int> psi;
typedef pair<int, string> pis;
typedef vector<int> vi;
typedef vector<double> vd;
typedef vector<long> vl;
typedef vector<long long> vll;
typedef vector<string> vs;
#pragma endregion


// Effective std
#pragma region ESTD
template<typename C, typename T>
constexpr int count(C& c, T t) { return count(ALL(c), t); }
template<typename C, typename F>
constexpr int count_if(C& c, F f) { return count_if(ALL(c), f); }
template<typename C, typename T, typename U>
constexpr void replace(C& c, T t, U u) { replace(ALL(c), t, u); }
template<typename C, typename F, typename U>
constexpr void replace_if(C& c, F f, U u) { (ALL(c), f, u); }
template<typename C>
constexpr void sort(C& c) { sort(ALL(c)); }
template<typename C, typename Pred>
constexpr void sort(C& c, Pred p) { sort(ALL(c), p); }
template<typename C>
constexpr void reverse(C& c) { reverse(ALL(c)); }
#pragma endregion


// ?´???°
#pragma region PRIME
bool is_prime(unsigned n) {
  switch(n) {
    case 0:
    case 1: return false;
    case 2: return true;
  }
  if (n%2==0) return false;
  for (unsigned i=3; i*i<=n; i+=2)
    if (n%i==0) return false;
  return true;
}
#pragma endregion


// ??§??????/?°?????????????
#pragma region TRANSFORM
void mutal_tr(string &s) {
  for(int i=s.size(); i--;) {
    if(islower(s[i])) s[i] = toupper(s[i]);
    else if (isupper(s[i])) s[i] = tolower(s[i]);
  }
}
void to_upper(string &s) { for(int i=s.size(); i--;) s[i] = toupper(s[i]); }
void to_lower(string &s) { for(int i=s.size(); i--;) s[i] = tolower(s[i]); }
#pragma endregion


// ??????
#pragma region SET
template<class T>
set<T> intersection(const set<T>& sa, const set<T>& sb) {
  set<T> ret;
  for(T a : sa) if(sb.find(a) != sb.end()) ret.insert(a);
  return ret;
}
#pragma endregion

// Union Find
#pragma region UF
struct UnionFind {
  vector<int> data;
  UnionFind(int size) : data(size, -1) {}
  bool union_set(int x, int y) {
    x = root(x); y = root(y);
    if(x!=y) {
      if(data[y] < data[x]) swap(x, y);
      data[x] += data[y]; data[y] = x;
    }
    return x != y;
  }
  bool find_set(int x, int y) { return root(x) == root(y); }
  int root(int x) { return data[x] < 0 ? x : data[x] = root(data[x]); }
  int size(int x) { return -data[root(x)]; }
};
#pragma endregion


// ?????°
#pragma region CONST_VAL
#define PI (2*acos(0.0))
#define EPS (1e-9)
#define MOD (int)(1e9+7)
#pragma endregion

int gcd(int m, int n)
{
    if((0==m)||(0==n)) return 0;
    while(m!=n) {
        if(m>n) m = m - n;
        else n = n - m;
    }
    return m;
}

int lcm(int m, int n)
{
    if((0==m)||(0==n)) return 0;
    return((m/gcd(m,n))*n);
}

int main() {
    int a, b;
    while(cin>>a>>b) {
        printf("%d %d", gcd(a,b), lcm(a,b));

    }
    return 0;
}

C++: #include<iostream>
using namespace std;
int main(){
    int a,b,c,x;
    cin >> a >> b;
    c=a*b;
    if(a>=b){
        x=a;
        a=b;
        b=x%b;
    }
    else if(a<b){
        b=a%b;
    }
    while(a!=0 || b!=0){
        x=a;
        a=b;
        b=x%b;
    }
    cout << a << " " << c/a << endl;
}