#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <map>
#include <cmath>
using namespace std;

int main(){
	double h, a, d; cin >> h >> a >> d;
	double cntmax = ceil(h / a);
	
	double minE = cntmax;
	for (int i = 0; i < cntmax; i++){
		double tmpH = h - a*i;
		
		minE = min(minE, i+1.5*ceil(tmpH/d));
	}
	cout << minE << endl;
	return 0;
}