bool ransom_note(vector<string> magazine, vector<string> ransom) {
    unordered_map<string, int> words;
    for (auto &it: magazine)
        words[it]++;
    for (auto &it: ransom) {
        if (words[it]>0)
            words[it]--;
        else
            return false;
    }
    return true;
}