#include <bits/stdc++.h>
#define rep(i, a) for (int i = 0; i < (a); i++)
#define rep2(i, a, b) for (int i = (a); i < (b); i++)
#define repr(i, a) for (int i = (a) - 1; i >= 0; i--)
#define repr2(i, a, b) for (int i = (b) - 1; i >= (a); i--)
using namespace std;
typedef long long ll;
const ll inf = 1e9;
const ll mod = 1e9 + 7;

int main() {
	double H, A, D;
	cin >> H >> A >> D;

	double ans = 1e18;

	for (ll i = 0; i * A <= H; i++) {
		double j = ceil((H - A * i) / D) * 1.5;
		ans = min(ans, i + j);
	}

	cout << ans << endl;

	return 0;
}