using System; using static System.Console; using System.Linq; using System.Collections.Generic; class Program { static int NN => int.Parse(ReadLine()); static int[] NList => ReadLine().Split().Select(int.Parse).ToArray(); static string[] SList(long n) => Enumerable.Repeat(0, (int)n).Select(_ => ReadLine()).ToArray(); public static void Main() { Solve(); } static void Solve() { var t = NN; var ans = new bool[t]; for (var u = 0; u < t; ++u) { var n = NN; var s = SList(n); ans[u] = Inf(n, s); } WriteLine(string.Join("\n", ans.Select(f => f ? "Yes" : "No"))); } static bool Inf(int n, string[] s) { var map = new string[n][]; for (var i = 0; i < n; ++i) map[i] = s[i].Split(); var flg = false; var maxlen = 0; for (var i = 0; i < n; ++i) { if (map[i][0] == "a") { if (map[i][1].Contains('a')) return true; maxlen = Math.Max(maxlen, map[i][1].Length); flg = true; } } if (!flg) return false; for (var i = 0; i < n; ++i) { if (!map[i][0].Contains('a') && map[i][0].Length <= maxlen) return true; } return false; } }