#include <iostream>
#include <cmath>
#include <vector>
#include <algorithm>
#include <string>
#include <map>
#include <set>
using namespace std;
typedef long long ll;

class Person {
public:
    void ChangeFirstName(int year, const string& first_name) {
        // добавить факт изменения имени на first_name в год year
        f_name[year] = first_name;
    }
    void ChangeLastName(int year, const string& last_name) {
        // добавить факт изменения фамилии на last_name в год year
        s_name[year] = last_name;
    }

    string GetName(const map<int, string> &dict, int year) {
        string res;
        vector<string> ss;
        vector<string> s;

        for (auto it = dict.rbegin(); it != dict.rend(); ++it)
            if (it->first <= year)
                ss.push_back(it->second);

        if (!ss.empty()) {
            s.push_back(ss[0]);
            res += s[0];
        }
        for (int i = 1; i < ss.size(); ++i)
            if (ss[i] != ss[i - 1])
                s.push_back(ss[i]);

        if (s.size() > 1) {
            res += " (";
            for (int i = 1; i < s.size(); ++i)
                if (!i || s[i] != s[i - 1]) {
                    res += s[i];
                    if (s.size() > 2 && i < s.size() - 1)
                        res += ", ";
                }
            res += ")";
        }

        return res;
    }

    string GetFullName(int year) {
        // получить имя и фамилию по состоянию на конец года year
        string res;
        for (auto it = f_name.rbegin(); it != f_name.rend(); ++it)
            if (it->first <= year) {res += it->second; break;}
        res += " ";
        for (auto it = s_name.rbegin(); it != s_name.rend(); ++it)
            if (it->first <= year) {res += it->second; break;}
        if (res == " ")
            res = "Incognito";
        else if (res[0] == ' ') {
            res.erase(0, 1);
            res += " with unknown first name";
        }
        else if (res[res.size() - 1] == ' ')
            res += "with unknown last name";
        return res;
    }

    string GetFullNameWithHistory(int year) {
        string res;
        res += GetName(f_name, year);
        res += " ";
        res += GetName(s_name, year);
        if (res == " ")
            res = "Incognito";
        else if (res[0] == ' ') {
            res.erase(0, 1);
            res += " with unknown first name";
        }
        else if (res[res.size() - 1] == ' ')
            res += "with unknown last name";
        return res;
    }

private:
    // приватные поля
    map<int, string> f_name;
    map<int, string> s_name;
};

/*int main() {
    Person person;

    person.ChangeFirstName(1900, "Eugene");
    person.ChangeLastName(1900, "Sokolov");
    person.ChangeLastName(1910, "Sokolov");
    person.ChangeFirstName(1920, "Evgeny");
    person.ChangeLastName(1930, "Sokolov");
    cout << person.GetFullNameWithHistory(1940) << endl;

    return 0;
}*/