#include <iostream>
#include <cmath>

int main() {
    int n, k;
    std::cin >> n >> k;

    if (n < k) {
        std::cout << 2;
    } else {
        double speed = 0.5 * k;

        int result = static_cast<int>(std::ceil(n / speed));
        std::cout << result;
    }
}