#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];
int main() {
  cin >> H >> A >> D;
  fill(dp, dp + 100100, INF);
  dp[0] = 0;
  for (int i = 1; i <= H; i++){
    if (i - A >= 0 && dp[i - A] != INF){
      dp[i] = min(dp[i], dp[i - A] + 1);
    }
    if (i - D >= 0 && dp[i - D] != INF){
      dp[i] = min(dp[i], dp[i - D] + 1.5);
    }
  }
  cout << dp[H] << endl;
  return 0;
}