Combination By Recursion(Factorial)

#include<bits/stdc++.h>
#define ll long long int
using namespace std;
ll recursive(ll n)
{
    if(n == 0 || n == 1)
        return 1;
    else
        return n*recursive(n-1);
}
int main()
{
    ll n, m, r;
    cin >> n >> r;
    m = (recursive(n)/(recursive(r)* recursive(n-r)));
    cout << m << endl;
    return 0;
}