#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=int(a);i<int(b);++i)
using namespace std;
typedef long long ll;
int INF = (1LL << 30) - 1;
int MOD = 1e9+7;
main(){
    int H,A,D;
    cin >> H >> A >> D;
    vector<double> ans(H+A+D,INF);
    ans[0] = 0;
    rep(i,1,H+1){
        if(i < A)ans[i] = 1.;
        else ans[i] = min(ans[i], ans[i - A] + 1);
        if(i < D)ans[i] = min(ans[i], 1.5);
        else ans[i] = min(ans[i], ans[i - D] + 1.5);
    }
    cout << ans[H] << endl;
}