#include <bits/stdc++.h>

#define REP(i, x, n) for(int i = x; i < (int)(n); i++)
#define rep(i, n) REP(i, 0, n)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define F first
#define S second
#define mp make_pair

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> P;

int main() {
  // ios_base::sync_with_stdio(false);
  int H, A, D;
  cin >> H >> A >> D;

  const double INF = 1e9;
  vector<double> dp(H + 1, INF);
  dp[0] = 0;

  rep(i, H + 1) {
    if(dp[i] == INF) continue;
    int d1 = min(H, i + A);
    dp[d1] = min(dp[d1], dp[i] + 1);
    int d2 = min(H, i + D);
    dp[d2] = min(dp[d2], dp[i] + 1.5);
  }

  cout << dp[H] << endl;

  return 0;
}