#include<iostream>
#include<algorithm>
using namespace std;

int main(void){
	int H, A, D;
	cin >> H >> A >> D;
	double e[10001];
	e[0] = 0;
	for (int i = 1; i <= H; i++)
		e[i] = min(e[max(0, i - A)] + 1, e[max(0, i - D)] + 1.5);
	cout << e[H] << endl;
	return 0;
}