bool cmp(const string& lhs, const string& rhs) {
    string l = lhs;
    string r = rhs;
    int l_size = l.size();
    int r_size = r.size();

    if (l_size < r_size) {
        r.resize(l_size);
    } else if (r_size < l_size) {
        l.resize(r_size);
    }

    return l < r;
}

template <typename RandomIt>
pair<RandomIt, RandomIt> FindStartsWith(
    RandomIt range_begin, RandomIt range_end,
    const string prefix) {

    auto r = equal_range(range_begin, range_end, prefix, cmp);

    return r;
}