func main()
	var n: int :: cui@inputInt()
	var m: int :: cui@inputInt()
	var t: int :: 0
	var p: int :: 0
	var ans: []char :: "Yes"
	for i(0, m - 1)
		var tNew: int :: cui@inputInt()
		var pNew: int :: cui@inputInt()
		if(tNew - t < (pNew - p).abs())
			do ans :: "No"
			break i
		end if
	end for
	do cui@print(ans)
end func