nyoj-兰州烧饼

#include <iostream>

using namespace std;

int main()
{
    int n,k;
    while(cin >> n >> k)
    {
              if(n <= k)
                  cout << 2 << endl;
              else
                 if((2*n)%k>0)
                    cout << (2*n/k) +1 << endl;
              else
                 if((2*n)%k == 0)
                    cout << n*2/k << endl; 
                    }
    return 0;
}