#include<stdio.h>
class gcd_lcm
{
public:
?int gcd(int a,int b);
?int lcm(int a,int b);
};
int gcd_lcm::gcd(int a,int b)//great common divisor;
{
?if(b==0)return a;
?else return gcd(b,a%b);
}
int gcd_lcm::lcm(int a, int b)//least common multiple;
{
?if(a*b==0)return 0;
?else return a*b/gcd(a,b);
}