DAO507 code c++

#include<bits/stdc++.h>
using namespace std;
int k,d;
int main()
{
    freopen("DAO507.inp","r",stdin);
    freopen("DAO507.out","w",stdout);
    cin>>k;
    s=0;
    while (k>2)
    {
        if (k%2==0)
        {
        	k=k/2;
        	d=d+4;
        }
    	else
        {
        	k--;
        	d=d+2;
        }
	}
    d=d+2;		//buoc dao tu 2 ve 1
    cout<<d;
}