#include <bits/stdc++.h>

#define mp make_pair
#define mt make_tuple
#define pb push_back
#define rep(i, n) for (int i = 0; i < (n); i++)

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<long, long> pll;

const int INF = 1 << 29;
const double EPS = 1e-9;
const int MOD = 100000007;

const int dx[] = {1, 0, -1, 0}, dy[] = {0, -1, 0, 1};
int H, A, D;
int main() {
  cin >> H >> A >> D;
  vector<double> dp(H + 1, INF);
  dp[0] = 0;
  for (int i = 0; i < H + 1; i++){
    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;
}