#include <iostream>

using namespace std;

int main() {
    int h, u, d;
    cin >> h >> u >> d;


    int denovi = 1;

    for(int zhelka = 0; zhelka + u < h; zhelka += u) {
        denovi += 1;

        zhelka -= d;
    }
    cout << denovi << endl;
    return 0;
}