Find LCM of two numbers in C++

C++ program to find LCM of two numbers

To find the LCM (Least Common Multiple) of two or more numbers, make multiple of numbers and choose common multiple. Then take lowest common multiple, this lowest common multiple is LCM of numbers. For example;

Suppose find LCM of 3 and 4
Multiple of 3 : 3, 6, 9, 12, 15, 18, 21, 24,.......
Multiple of 4 : 4, 8, 12, 16, 20, 24, 28,.....

So, common multiple of 3 and 4 is 12, 24
and Least Common Multiple is 12
LCM of 3 and 4 is: 12

#include<iostream.h>
#include<conio.h>

void lcm(int,int);

void main()
{
    int a,b;
    clrscr();
    cout<<"Enter two numbers: ";
    cin>>a;
    cin>>b;
    lcm(a,b);
    getch();
  //  return 0;
}

//function to calculate l.c.m
void lcm(int a,int b)
{
    int m,n;

    m=a;
    n=b;

    while(m!=n)
    {
	if(m < n)
	{
	m=m+a;
	}
	else
	{
	    n=n+b;
	    }
    }

    cout<<"\nL.C.M of "<<a<<" and "<<b<<" is "<<m;
}

Enter any two number: 
3
15
L.C.M of 3 & 15 is 3