LCM of Two Number Program in C++

// LCM of two number is a*b divided by gcd/hcf of two number
#include<bits/stdc++.h>
#include<stdio.h>
using namespace std;
int __gcd(int a,int b)
{
if(b==0)
return a;
return __gcd(b,a%b);
}
int main()
{
int a=12;
int b=6;
int lcm=(a*b)/__gcd(a,b);
cout<<lcm;
}