import std.stdio, std.algorithm, std.array, std.conv, std.typecons;

void main() {
	string[] anss;
	auto T = readln[0 .. $-1].to!uint;
	
	test:
	foreach (t; 0 .. T) {
		auto N = readln[0 .. $-1].to!uint;
		string[][] XYs;
		foreach (n; 0 .. N) {
			XYs ~= readln.split;
		}
		
		ulong bbb_lens_max;
		foreach (XY; XYs) {
			if (XY[0] == "a")
				if (XY[1].count("a") != 0) {
					anss ~= "Yes";
					continue test;
				}
				else
					bbb_lens_max = max(bbb_lens_max, XY[1].length);
				
		}
		
		foreach (XY; XYs) {
			if (XY[0].count("a") == 0 && XY[0].length <= bbb_lens_max) {
				anss ~= "Yes";
				continue test;
			}
		}
		
		anss ~= "No";
	}
	
	foreach (ans; anss) writeln(ans);
}