#include <bits/stdc++.h>		

#define fi first
#define se second
#define endl '\n'


using namespace std;
using LL = long long;

const int N = 1e5 + 9; 
const int mod = 998244353;


int n;
set<string> se[25];
string team,status;
char id;

void solve()
{
	cin >> n;	
	for (int i = 1;i <= n;i ++)
	{
		cin >> team >> id >> status;
		if (status == "accepted")
			se[id - 65].insert(team);
			// cout << id - 65 << endl;
	}
	
	int ans;
	int maxv = 0;
	for (int i = 0;i < 24;i ++)
		if (se[i].size() > maxv) maxv = se[i].size(),ans = i;

	// cout << ans << endl;
	cout << char('A' + ans) << endl;
}

int main()
{
	ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
	int _ = 1;
	cin >> _;
	while(_--) solve();
	
	return 0;
}