TACERTOSAPORRA

#include <iostream>
#include <string>

using namespace std;

struct HashTable {
private:
    string keys[101];
    int numberKeys;

public:
    HashTable() {
        for (int i = 0; i < 101; i++)
            this->keys[i] = "";

        this->numberKeys = 0;
    }

    int find(string key) {
        int index = hash(key);
        for (int i = 0; i < 20; i++) {
            int newIndex = index + offset(i);
            newIndex %= 101;

            if (this->keys[newIndex] == key)
                return newIndex;
        }

        return -1;
    }

    void insert(string key) {
        if (find(key) == -1) {
            int index = hash(key);
            bool done = false;

            for (int i = 0; i < 20 && !done; i++) {
                int newIndex = index + offset(i);
                newIndex %= 101;

                if (this->keys[newIndex] == "") {
                    this->keys[newIndex] = key;
                    done = true;
                }
            }

            this->numberKeys++;
        }
    }

    void remove(string key) {
        int index = find(key);
        if (index != -1) {
            this->keys[index] = "";
            this->numberKeys--;
        }
    }

    int getNumberKeys() {
        return this->numberKeys;
    }

    void getKeys() {
        for (int i = 0; i < 101; i++) {
            if (this->keys[i] != "")
                cout << i << ":" << this->keys[i] << endl;
        }
    }

private:
    int hash(string key) {
        int sum = 0;
        for (int i = 0; i < key.length(); i++)
            sum += key[i] * (i + 1);

        sum *= 19;
        return sum % 101;
    }

    int offset(int attempt) {
        int result = attempt * attempt;
        result += 23 * attempt;
        return result;
    }
};

int main() {
    int numberTestCases, numberOperations;
    cin >> numberTestCases;

    for (int i = 0; i < numberTestCases; i++) {
        cin >> numberOperations;
        HashTable hashTable;

        for (int j = 0; j < numberOperations; j++) {
            string input, key = "";
            cin >> input;

            for (int k = 4; k < input.length(); k++)
                key += input[k];

            if (key.length() > 0) {
                if (input[0] == 'A')
                    hashTable.insert(key);
                else
                    hashTable.remove(key);
            }
        }

        cout << hashTable.getNumberKeys() << endl;
        hashTable.getKeys();
    }
}