A.宇宙的终结

Code(伪代码):

void solve() {
    int left, right; cin >> left >> right;
    auto check1 = [&](int n) {
        for (int i = 2; i <= sqrt(n); i++) {
            if (n % i == 0) {
                return false;
            }
        }
        return true;
    };
    auto check2 = [&](int val) {
        return val >= left && val <= right;
    };
    for (int i = 2; i <= 20; i++) {
        for (int j = i + 1; j <= 20; j++) {
            for (int k = j + 1; k <= 20; k++) {
                if (check1(i) && check1(j) && check1(k) && check2(i * j * k)) {
                    cout << i * j * k;
                    return ;
                }
            }
        }
    }
    cout << -1;
    return ;
}