string check_current_word(string last_long_word, string next_long_word) {
    if (next_long_word.length() > last_long_word.length() || last_long_word.empty()) {
        last_long_word = next_long_word;
    }
    return last_long_word;
}

int task6() {
    string s, current_long_word, last_long_word;
    getline(cin, s);
    for (int i = 0; i < s.length(); i++) {
        if (s[i] != ' ') {
            current_long_word.push_back(s[i]);
        }
        if (s[i] == ' ' || i == s.length() - 1) {
            last_long_word = check_current_word(last_long_word, current_long_word);
            current_long_word.clear();
        }
    }
    cout << last_long_word;
    return 0;
}