#include <bits/stdc++.h>
using namespace std;
map<string,int> m;
int a[27];
bool vis[100000][27];

auto solve() {
    fill(a,a+27,0);
    fill(vis[0],vis[0]+27*100000,0);
    int n;
    cin>>n;
    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++;
        }
        if(vis[m[s1]][zm - 'A'+1] and s2 == "accepted") {
            a[zm - 'A'+1]++;
        }
    }
    int ans = 0;
    for (int i = 1; i <= 26; i++) {
        ans = max(a[i],ans);
    }
    cout<<char(ans+65);
}

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