#include <bits/stdc++.h>
using namespace std;
map<string, int> m;

auto solve() {
    int n;
    cin >> n;
    vector a(27, 0);
    vector vis(n + 5, vector(27, false));
    // index_of_range
    int j = 1;
    for (int i = 1; i <= n; i++) {
        string s1, s2;
        char zm;
        cin >> s1;
        cin >> zm;
        cin >> s2;
        if (m.find(s1) == m.end()) {
            m[s1] = j++;
        }
        try {
            if (!vis.at(m[s1]).at(zm - 'A' + 1) and s2 == "accepted") {
                a[zm - 'A' + 1]++;
                vis.at(m[s1]).at(zm - 'A' + 1) = true;
            }
        } catch (...) {
            cout << '[' << m[s1] << "]\n";
            exit(0);
        }
    }
    int ans = 0, ans_i = 0;
    for (int i = 1; i <= 26; i++) {
        if (a[i] > ans) {
            ans = a[i];
            ans_i = i;
        }
    }
    cout << char(ans_i + 64) << endl;
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int64_t t;
    cin >> t;
    while (t--)
        solve();
    return 0;
}