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>
#include<algorithm>
#include<vector>
int main(){
	int a, b, product;

  	while (std::cin >> a >> b) {
    	product = a * b;
		std::vector<int> v = {a, b};
    	while (v.at(0) != v.at(1)) { 
      		std::sort(v.begin(), v.end(), std::greater<int>());
      		v.at(0) = v.at(0) - v.at(1);
		}	
    	std::cout << v.at(0) << " " << product/v.at(1) << std::endl;	
  	}
	return 0;
}

C++: #include <iostream>

#define CASE double

using namespace std;

int GCD(CASE x, CASE y)
{
	if (x == 0 || y == 0)
		return x + y;
	else
	{
		if (x >= y)
		{
			x = x - y;
			GCD(x, y);
		}
		else
		{
			y = y - x;
			GCD(x, y);
		}
	}
}

int main(){
	CASE a, b;
	unsigned long int d, l;
		cin >> a;
		cin >> b;
		d = (unsigned long int)GCD(a, b);
		l = a * b / d;
		cout << d << " " << l << endl;
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

#define FOR(i,l,r) for(int i = (l);i < (r);i++)
#define ALL(x) (x).begin(),(x).end()
template<typename T> bool chmax(T& a,const T& b){return a < b ? (a = b,true) : false;}
template<typename T> bool chmin(T& a,const T& b){return b < a ? (a = b,true) : false;}
typedef long long ll;

long long gcd(long long x,long long y)
{
	return y ? gcd(y,x % y) : x;
}

long long lcm(long long x,long long y)
{
	return x / gcd(x,y) * y;
}

ll A,B;

int main()
{
	while(~scanf("%lld%lld",&A,&B)){
		printf("%lld %lld\n",gcd(A,B),lcm(A,B));
	}

	return 0;
}

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

int main() {
    
    int a,b;
    while(cin >> a >> b){
        for(int i = a;i > 1;i--){
            if(b%i == 0 && a%i == 0){
                cout << i << "\n";
                break;
            }
        }
        for(int i = a;i < 2000000000;i++){
            if(i%a == 0 && i%b == 0){
                cout << i << "\n";
                break;
            }
        }
    }
    
return 0;
}

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

void compare(long int* a, long int* b){
  long int tem;
  if(*a < *b){
    tem = *a;
    *a = *b;
    *b = tem;
  }
}


int main(){
  long int a, b, k;
  long int x[1000][2];
  int n = 0;


  while(cin >> a >> b){
    k = a * b;
    while(1){
      compare(&a, &b);
      a = a - b;
      if(a == b)
        break;
    }
    x[n][0] = a;
    x[n][1] = k / a;
    n++;
  }

  for(int i = 0; i < n; i++)
    cout << x[i][0] << " " << x[i][1] << '\n';

  return 0;
}

C++: #include<iostream>
#include<cstdio>
#include<utility>
#include<climits>
#include<cmath>
using namespace std;

int main()
{
	long a, b;
	long c, d, e;
	long gcd, lcm;


	while (cin >> a >> b)
	{	
		c = a, d = b;
		while (d != 0)
		{
			e = c % d;
			c = d; d = e;
		}

		gcd = c;
		lcm = a * b /gcd;

		cout << gcd << " " << lcm << endl;
	}

	return 0;
}

C++: #include <iostream>                                             
using namespace std;                                            
typedef long long ll;                                           
                                                                
int GCD(ll a,ll b) {                                            
  if (b==0) {                                                   
    return a;                                                   
  }                                                             
  return GCD(b,a%b);                                            
}                                                               
                                                                
int main() {                                                    
  ll a, b;                                                      
  while (cin >> a >> b) {                                       
    cout << GCD(a,b) << " " << a/GCD(a,b)*b << endl;            
  }                                                             
  return 0;                                                     
}

C++: /*
    ????????°??§???????????¨????????????
*/

#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>
#include <limits.h>
#include <iostream>
#include <algorithm>
#include <string>
#include <iterator>
#include <vector>
#include <map>
#include <utility>
#define LLU unsigned long long int
#define LL long long int
#define LD long double
using namespace std;
#define LLUmax ULLONG_MAX
#define LLmax LLONG_MAX
#define dmax INT_MAX
#define vd vector<int>
#define vLL vector<long long int>
#define vLLU vector<unsigned long long int> 
#define pb push_back
#define mp make_pair
#define fi first
#define sec second
#define debug printf("asd\n")
#define debugd(a) printf("--%d\n",a)
#define debugdd(a,b) printf("--%d %d\n",a,b)
#define debugarr(a,b) for(int i=0 ; i<b ; i++)printf("%d ",a[i]);printf("\n")
#define newline printf("\n")
#define forin(a,b,c) for(int a=b ; a<c ; a++)
#define forde(a,b,c) for(int a=b ; a<c ; a--)


inline void scd(int &a){scanf("%d",&a);}
inline void scdd(int &a,int &b){scanf("%d %d",&a,&b);}
inline void sctd(int &a,int &b,int &c){scanf("%d %d %d",&a,&b,&c);}
inline void scdlld(long int &a,long int &b){scanf("%I64d %I64d",&a,&b);}
inline void sclld(long long int &a){scanf("%I64d",&a);}

#define scarrd(a,b) for(int index=0 ; index<b ; index++)scanf("%d",&a[index])
#define prdlld(a,b) printf("%I64d %I64d",a,b)
#define prdd(a,b) printf("%d %d",a,b)
#define prd(a) printf("%d",a)
#define prarr(a,b) for(int i=0 ; i<b ; i++)printf("%d ",a[i])
#define iniarr(a,b) for(int i=0 ; i<b ;i++)a[i]=0
#define arr(a,b) int *a=(int *)malloc(b*sizeof(int))
#define llarr(a,b) long long int *a=(long long int *)malloc(b*sizeof(long long int))
#define st(a,b) char *a=(char *)malloc(b*sizeof(char))
#define grav 9.8
#define pi 3.14159265

LL gcd(LL a,LL b)
{
	if(b==0)
	return a;
	
	return gcd(b,a%b);
}

int main()
{
	LL a,b;
	while(scanf("%lld %lld",&a,&b)!=EOF)
	{
		LL gcdz=gcd(a,b);
		LL lcm=(a*b)/gcdz;
		printf("%lld %lld\n",gcdz,lcm);
	}
	
	return 0;
}

C++: #include <bits/stdc++.h>

using namespace std;

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  
  int a, b;
  while (cin >> a >> b) {
    int c = a, d = b;
    int e;
    while ((e = c % d) > 0) {
      c = d;
      d = e;
    }
    cout << d << " " << a / d * b << endl;
  }
}

C++: #include <stdio.h>
#include <math.h>

int u(int a, int b);
int l(int a, int b);

int main(){
  int a, b;
  int gcd, lcm;
  
  while(scanf("%d", &a)!=EOF){
    scanf("%d", &b);
    gcd = u(a, b);
    lcm = l(a, b);
printf("%d %d\n",lcm, gcd);
    //std::cout << lcm << " " << gcd << std::endl;
  }
  
  return 0;
}

int u(int a, int b){
  while(a==1 || b==1){
    if(a>=b){
      a = a % b;
    }else{
      b = b % a;
    }
  }
  
  if(a==1) return b;
  else     return a;
}

int l(int a, int b){
  int i = 2;
  
  while(1){
    if(a%i==0){
      if(b%i==0) return i;
      else i++;
    }else{
      i++;
    }
  }
}

C++: #include <iostream>
#include <cmath>

int gcd(int x,int y);
int lcm(int x,int y);

int main(){
  int a,b;
using namespace std;

  while(1){
  cin >> a >> b;
  if(cin.eof())break;
  cout << gcd(a,b)<<" "<<lcm(a,b)<<endl;
  }
  return 0;
}

int gcd(int x,int y){
  int z;
  while(y!=0){
  z = x%y;
  x = y; 
  y = z;
  }
  return x;
}

int lcm(int x,int y){
  int g = gcd(x,y);
  return x/g*y;
}