#define _USE_MATH_DEFINES #include <algorithm> #include <cstdio> #include <functional> #include <iostream> #include <cfloat> #include <climits> #include <cstring> #include <cmath> #include <map> #include <queue> #include <random> #include <set> #include <sstream> #include <stack> #include <string> #include <time.h> #include <vector> using namespace std; typedef long long ll; typedef unsigned long long ull; typedef pair<int, int> i_i; typedef pair<int, ll> i_ll; typedef pair<ll, int> ll_i; typedef pair<double, int> d_i; typedef pair<ll, ll> ll_ll; typedef pair<double, double> d_d; struct edge { int u, v; ll w; }; ll MOD = 1000000007; ll _MOD = 1000000009; double EPS = 1e-10; int main() { int H, A, D; cin >> H >> A >> D; vector<double> dp(H + 1, DBL_MAX); dp[0] = 0; for (int h = 1; h <= H; h++) { int ha = max(0, h - A); dp[h] = min(dp[h], dp[ha] + 1); int hd = max(0, h - D); dp[h] = min(dp[h], dp[hd] + 1.5); } printf("%.10f\n", dp[H]); }