#include <iostream>
#include <algorithm>
#include <cstring>
#include <cstdio>
#include <cmath>
#include <stack>
#include <set>
#include <map>
#include <queue>
#include <climits>
#include <bitset>
#define PI 3.1415926

using namespace std;

int main()
{
    double n, p;
    while (cin >>n >>p)
    {
        double temp = n * 2 / p;
        if (temp <= 2)
            cout <<"2" <<endl;
        else
            cout <<ceil(temp) <<endl;
    }

    return 0;
}