#include <iostream>
#include <string>
#include <algorithm>
#include <iomanip>
#include <vector>
#include <map>
#include <cmath>
#include <queue>
#include <utility>
#include <functional>
#include <deque>
#include <cctype>
#include <stack>
#include <bitset>
#include <set>

using ll = long long;
using namespace std;
typedef unsigned long long ull;
typedef pair<ll, ll> P;

const ll MOD = 1000000007;
const ll INF = 1 << 30;
const ll INF2 = 9000000000000000000LL;
const double INF3 = 900000000000000;
const int dx[4] = { 1,0,-1,0 }, dy[4] = { 0,1,0,-1 };
const int tx[8] = { -1,0,1,-1,1,-1,0,1 }, ty[8] = { -1,-1,-1,0,0,1,1,1 };
#define ALL(x) (x).begin(),(x).end()


int main() {
	int h, a, d;
	cin >> h >> a >> d;
	double dp[10010];
	for (int i = 0;i <= h + 2;i++)dp[i] = INF3;
	dp[0] = 0;
	for (int i = 0;i < h + 1;i++) {
		if (dp[i] == INF3)continue;
		dp[min(h,i + a)] = min(dp[min(h,i + a)], dp[i] + 1);
		dp[min(h,i + d)] = min(dp[min(h,i + d)], dp[i] + 1.5);
	}
	cout << dp[h] << endl;
}