Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

func gcd(num1, num2 int) int {
	if num2 == 0 {
		return num1
	}
	num3 := num1 % num2
	return gcd(num2, num3)
}

func lcm(num1, num2 int) int {
	if num1%num2 != 0 {
		num3 := gcd(num1, num2)
		for i := 1; ; i++ {
			check := num3 * i
			if check%num1 == 0 && check%num2 == 0 {
				return check
			}
		}
	} else {
		return num1
	}
}

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	for scanner.Scan() {
		row := strings.Fields(scanner.Text())
		nums := []int{}

		for _, v := range row {
			num, _ := strconv.Atoi(v)
			nums = append(nums, num)
		}
		fmt.Println(gcd(nums[0], nums[1]), lcm(nums[0], nums[1]))
	}
}

C++: //C++14 (Clang 3.8.0)

#include <vector>
#include <list>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <string>
using namespace std;
typedef pair<int,int> P;
typedef unsigned long long ll;
ll gcd(ll x,ll y){
    ll ma=max(x,y),mi=min(x,y),ama=ma%mi;
    if(ama==0) return mi;
    else return gcd(mi,ama);
}
ll lcm(ll x,ll y){
    ll g=gcd(x,y);
    if(g==1) return x*y;
    return g*lcm(x/g,y/g);
}
int main(){
    
    for(int i=0;i<50;i++){
        ll a,b;
        cin>>a>>b;
        cout<<gcd(a,b)<<" "<<lcm(a,b)<<endl;
    }
    return 0;
};

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

int main(){

  long long int a,b,c,r,s;

  while(cin >> a >> b){

    s=a*b;

    while(b!=0){

      c=a/b;
      r=a%b;
      a=b;
      b=r;

    }

    cout << a << ' ' << s/a <<  endl;
  }

  return 0;
}

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

int main() {
	int a = 0;
	int b = 0;
	int tmp = 0;
	int d = 1;
	int a_bk = 0;
	int b_bk = 0;

	while (cin >> a >> b) {
		if (a < b) {
			tmp = b;
			b = a;
			a = tmp;
		}

		a_bk = a;
		b_bk = b;
		d = 1;

		for (int c = 2; c <= a_bk; c++) {
			while (a%c == 0 && b%c == 0) {
				a /= c;
				b /= c;
				d *= c;

			}
		}
		cout << d << '\n';
		d = a_bk * b_bk / d;
		cout << d << "\n";

	}
	return 0;
}

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

int gcd(int x,int y);

int main(){
   while(true){
      int a,b;
      cin >> a >> b;
      if(cin.eof())
         break;
      int c=gcd(a,b);
      cout << ' ' << a/c*b << endl;
   }
   return 0;
}

int gcd(int x,int y){
   if(b==0)
      return x;
   return gcd(b,a%b);
}

C++: // g++ -std=c++11 temp.cpp
#include <bits/stdc++.h>
using namespace std;

#define FOR(i,a,b) for(int i=(int)(a);i<(int)(b);i++)
#define REP(i,n) FOR(i,0,n)
#define EACH(itr,v) for(auto itr:v)
#define pb(s) push_back(s)
#define mp(a,b) make_pair(a,b)
#define all(x) (x).begin(),(x).end()
#define dbg(x) cout<<#x"="<<x<<endl

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> P;
typedef pair<P, int> PPI;

#define INF INT_MAX/3

#define MAX_N 1000

ll a,b;

ll gcd(ll x, ll y){
	if(y==0) return x;
	return gcd(y, x%y);
}

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

int main(){
	while(scanf("%lld %lld", &a, &b)!=EOF){
		cout<<gcd(a,b)<<" "<<lcm(a,b)<<endl;
	}
	return 0;
}

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

using namespace std;

int gcd(int a,int b)
{
    if(b == 0 || a == b)
        return a;
    else
        return gcd(b,a%b);
}
int lcm(int a, int b)
{
    int g = gcd(a,b);
    return (a / g) * b;
}

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

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


 int euclid(int a, int b){
  if (b < a) {
    int c = b;
    b=a;
    a=c;
  }
  int r=a%b ;
  while(r)
  {
  a=b;
  b=r;
  r=a%b;
  }
return b;
}
int main(){
  int a,b;
  while(cin >> a >> b)
    cout << euclid(a,b) << " "<<a*b/(euclid(a,b));
}

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

int gcd( unsigned int, unsigned int );
int main(void)
{
	unsigned int a, b, g, l;

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

	return 0;
}

int gcd( unsigned int a, unsigned int b ){
	int n, i;
	unsigned int tmp[4];

	tmp[0] = std::max( a, b );
	tmp[1] = std::mix( a, b );

	for( n = 0;; n++ ){
		for( i = 1;(tmp[( n + 2 ) % 3 ] = tmp[ n % 3 ] - tmp[( n + 1 ) % 3 ] * i ) >= tmp[( n + 1 ) % 3]; i++ ){
			if( tmp[( n + 2 ) % 3 ] == 0 ){
				return tmp[( n + 1 ) % 3 ];
			}
		}
		if( n > 2000000000 ){
			return -1;
		}
	}

	return -1;
}

C++: #include <iostream>

int main(){

	u_int a, b;

	while(std::cin >> a >> b){

		u_int minmul; //least common multiple
		u_int maxdivi = 1; //greatest common divisor
		u_int small;

		if(a > b)
			small = b;
		else
			small = a;

		for(int i = 2; i <= small; i++){
			if(a % i == 0  &&  b % i == 0){
				maxdivi = maxdivi * i;
				i = 2;
			}
		}
		minmul = a * b / maxdivi;

	std::cout << maxdivi << minmul << std::endl;

	}

	return 0;
}

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

long gcd(int a,int b){
	if(a == 0)return b;
	else if(a > b)return gcd(a%b,b);
	return gcd(b%a,a);
}

int main(){
	long long a,b;
	while(!cin.eof()){
		cin >> a >> b;
		long g = gcd(a,b);
		cout << g << " " << a*(b/g) << endl;
	}
	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){
      if(a == b)
        break;
      compare(&a, &b);
      a = a - b;
    }
    cout << "!!\n";
    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 <cstdio>
#include <iostream>
using namespace std;

int main(){
  long a, b;
  long l, m, n;
  while (scanf("%d %d", &a, &b) != EOF){
    cin >> a >> b;
    m = a;
    n = b;

    while (1){
      if (m <= n){
        int t = m;
        m = n;
        n = t;
      }

      if (n == 0){
        cout << m << " " << a * b / m << "\n";
        break;
      }

      l = m % n;
      m = n;
      n = l;

    }

    if (a <= 0 || b <= 0){
      break;
    }
  }

  return 0;
}

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

#define REP(i, s, n) for(int i = s; i < n; ++i)
#define rep(i, n)		 REP(i, 0, n)
#define SORT(c)			 sort((c).begin(), (c).end())
#define IINF					INT_MAX
#define LLINF					LLONG_MAX
#define DEBUG					false

int main(){
    long long int a,b,r=1;
    cin>>a>>b;
    if(a<b){
        long long int temp;
        temp=b;
        b=a;
        a=temp;
    }
    long long int tempa=a,tempb=b;
    r=b;
    b=a;
    while(r!=0){
        a=b;
        b=r;
        r=a%b;

    }
    long long ans=tempa*tempb/b;
    cout<<b<<" "<<ans<<endl;
    return 0;
}

C++: #include <iostream>

using namespace std;

void swap(int *a, int *b)
{
	if(*b > *a) {
		int temp = *a;
		*a = *b;
		*b = temp;
	}
}

int main()
{
	int a, b;

	while (cin >> a >> b)
	{
		int A = a, B = b;
		while (a != b) {
			swap(&a, &b);

			a -= b;
		}

		cout << a << ' ' << (A/a)*B << endl;
	}

	return 0;
}

C++: #include <iostream>

/* ユークリッドの互除法 */
int _euclidean_algorithm(int a, int b)
{
    if (a % b == 0){
        return b;
    }
    return _euclidean_algorithm(b, a % b);
}

/* Greatest common divisor */
int gcd(int a, int b)
{
    return _euclidean_algorithm(a, b);
}

/* Least common multiple */
int lcm(int a, int b)
{
    return (a / gcd(a, b) * b);
}

int main(void)
{
    int a, b;
    
    while (std::cin >> a >> b){
        std::cout << gcd(a, b) << " " << lcm(a, b) << std::endl;
    }
    
    return 0;
}