n = int(input()); s = input() i = 0; ans = "Yes" while i<n: if i==n-1 and s[i]=="?": i += 1 elif s[i]=="n" or s[i:i+2] in {"??","?n","?w"}: i += 1 elif s[i:i+2] in {"wa","wo","w?","?a","?o"}: i += 2 else: ans = "No"; i += 1 print(ans)