#include <iostream>
#include <vector>
#include <forward_list>

using namespace std;

static const int hash_map_size = 10003;

int polynom_hash(const string& key) {
    const int a = 123;

    int h = key[0];
    for (int i = 1; i < key.size(); ++i) {
        h = (key[i] + a * h) % hash_map_size;
    }

    return h;
}

int main() {
    vector <forward_list <pair<string, int>>> v(hash_map_size);

    int number_of_operations;
    cin >> number_of_operations;

    for (int i = 0; i < number_of_operations; ++i) {
        string command;
        string key;
        cin >> command >> key;
        auto& chain = v[polynom_hash(key)];
        bool operation_complete = false;

        if (command == "put") {
            int value;
            cin >> value;
            for (auto& elem : chain) {
                if (elem.first == key) {
                    elem.second = value;
                    operation_complete = true;
                    break;
                }
            }
            if (!operation_complete) {
                chain.emplace_front(key, value);
            }
            continue;
        }

        if (command == "get") {
            for (const auto& elem : chain) {
                if (elem.first == key) {
                    cout << elem.second << '\n';
                    operation_complete = true;
                    break;
                }
            }
            if (!operation_complete) {
                cout << -1 << '\n';
            }
            continue;
        }

        if (command == "delete") {
            auto slow = chain.begin();
            auto fast = chain.begin();

            while (fast != chain.end() && fast->first != key) {
                slow = fast;
                fast++;
            }

            if (fast == chain.end()) {
                cout << "error" << '\n';
                continue;
            }

            if (fast != slow) {
                chain.erase_after(slow);
            } else {
                chain.pop_front();
            }
            cout << "ok" << '\n';
        }
    }

    return 0;
}