#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;
double dp[100100];

double memo(int H){
  if (H <= 0)return 0;
  if (dp[H] >= 0){
    return dp[H];
  }
  dp[H] = min(1 + memo(H - A), 1.5 + memo(H - D));
  return dp[H];
}


int main() {
  cin >> H >> A >> D;
  memset(dp, -1, sizeof(dp));
  memo(H);
  cout << dp[H] << endl;
  return 0;
}