#include <algorithm>
#include <iostream>

using namespace std;

int H, A, D;

int main() {
	cin >> H >> A >> D;
	int na = (H - 1) / A + 1;
	double res = na;
	for (int i = 0; i < na; i++) {
		int nd = (H - i * A - 1) / D + 1;
		res = min(res, i + nd * 1.5);
	}
	cout << res << endl;
	return 0;
}