#include <iostream>
#include <map>
#include <set>
using namespace std;

int main() {
    int t;
    cin >> t;
    
    while (t--) {
        int n;
        cin >> n;
        
        // Map to track which teams solved which problems
        map<char, set<string>> solved_problems;
        
        for (int i = 0; i < n; ++i) {
            string team_name, result;
            char problem_id;
            cin >> team_name >> problem_id >> result;
            
            // Only consider "accepted" submissions
            if (result == "accepted") {
                solved_problems[problem_id].insert(team_name);
            }
        }
        
        // Find the easiest problem
        char easiest_problem = 'Z' + 1; // Initialize with a lexicographically large value
        int max_solved = 0;
        
        for (auto& entry : solved_problems) {
            char problem_id = entry.first;
            int teams_solved = entry.second.size();
            
            if (teams_solved > max_solved || (teams_solved == max_solved && problem_id < easiest_problem)) {
                max_solved = teams_solved;
                easiest_problem = problem_id;
            }
        }
        
        cout << easiest_problem << endl;
    }
    
    return 0;
}