func main()
	var n: int :: cui@inputInt()
	var dic: dict<[]char, int> :: #dict<[]char, int>
	var ans: bool :: false
	for loop(1, n)
		var ab: []char :: cui@input()
		if(dic.get(ab, &) = 1)
			do ans :: true
			break loop
		end if
		do dic.add(ab, 1)
	end for
	do cui@print((ans ?("Yes", "No")) ~ "\n")
end func