573 - The Snail

#include <bits/stdc++.h>

using namespace std;

#define ll long long
#define endl '\n'
#define sz(x) int(x.size())
#define all(x) x.begin(), x.end()

int main() {
    ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    double h, u, d, f;
    while (scanf("%lf %lf %lf %lf", &h, &u, &d, &f), h) {
        int day = 1;
        double curr_pos = 0;
        bool can = true;
        f = u * (f / 100);
        for (; day; day++) {
            curr_pos += u;
            if (curr_pos > h) break;
            u = max(double(0), u - f);
            curr_pos -= d;
            if (curr_pos < 0) {
                can = false;
                break;
            }
        }
        cout << (can ? "success" : "failure") << " on day " << day << endl;
    }
}