func main()
	var n: int :: cui@inputInt()
	var s: []char :: cui@input()
	
	var ans: bool :: true
	var prev: char :: '-'
	for i(0, n - 1)
		switch(s[i])
		case 'w'
			if(i = n - 1)
				do ans :: false
			else
				if(s[i + 1] <> 'a' & s[i + 1] <> 'o' & s[i + 1] <> '?')
					do ans :: false
				else
					do s[i + 1] :: 'a'
				end if
			end if
		case 'a', 'o'
			if(prev <> '?' & prev <> 'w')
				do ans :: false
			end if
		case 'n'
		case '?'
		default
			do ans :: false
		end switch
		do prev :: s[i]
	end for
	do cui@print((ans ?("Yes", "No")) ~ "\n")
end func