use std::io::Read;

fn main() {
	let mut s = String::new();
	std::io::stdin().read_to_string(&mut s).ok();
	let mut l = s.lines();
	for _ in 0..l.next().unwrap().parse().unwrap() {
		let n: Vec<usize> =
			l.next().unwrap().split(' ').flat_map(str::parse).collect();
		let mut c = vec![0; n[0]];
		for _ in 0..n[1] {
			l.next()
				.unwrap()
				.split(' ')
				.flat_map(str::parse::<usize>)
				.for_each(|i| c[i - 1] += 1);
		}
		c.sort();
		c.dedup();
		println!("{}", if c.len() < n[0] { "Yes" } else { "No" })
	}
}