DAO507 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;
    d=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;
}