#include <bits/stdc++.h>
using namespace std;
int main()
{
    int n, m, p = 0;
    cin >> n >> m;
    if (n == 1)
    {
        cout << n / m << endl;
    }
    else
    {
        if (n % 4 == 0)
        {
            n = n / 4;
            for (int i = 1; i <= n; i++)
            {
                if ((m * i) == n)
                {
                    p = i;
                }
            }
 
            cout << p * 4 << endl;
        }
        else
        {
            n = n / 2;
            for (int i = 1; i <= n; i++)
            {
                if ((m * i) == n)
                {
                    p = i;
                }
            }
 
            cout << p * 2 << endl;
        }
    }
}