#include <bits/stdc++.h>
using namespace std;

int main() {
    int H, A, D;
    cin >> H >> A >> D;
    double memo[10010];

    for (int i = 1; i <= H; i++) {
        memo[i] = min(
            memo[max(0, i - A)] + 1,
            memo[max(0, i - D)] + 1.5);
    }
    cout << memo[H] << endl;
}