func main()
	var t: int :: cui@inputInt()
	for(1, t)
		var n: int :: cui@inputInt()
		var m: int :: cui@inputInt()
		var graph: []list<int> :: #[n]list<int>
		for i(0, n - 1)
			do graph[i] :: #list<int>
		end for
		for(1, m)
			var a: int :: cui@inputInt() - 1
			var b: int :: cui@inputInt() - 1
			do graph[a].add(b)
			do graph[b].add(a)
		end for
		var map: dict<int, bool> :: #dict<int, bool>
		var ans: bool :: false
		for i(0, n - 1)
			var num: int :: ^graph[i]
			if(map.exist(num))
				do ans :: true
				break i
			end if
			do map.add(num, true)
		end for
		do cui@print((ans ?("Yes", "No")) ~ "\n")
	end for
end func