acpc2016day1B.cpp

signed main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(0);

    int A, B, N;
    cin >> A >> B >> N;

    int ans = inf;
    rep2(a, 1, N + 1) {
        rep2(b, 1, N + 1) {
            if (B % b == 0) {
                ans = min(ans, abs(A - a * (B / b)));                
            }
        }
    }
    cout << ans << endl;
}