code: def check_valid(s: str):
      cnt = 0
      for ch in s:
          if ch == "(":
              cnt += 1
          elif ch == ")":
              cnt -= 1
          else:
              return False
          if cnt < 0:
              return False
      return cnt == 0
  
label_desc: Use image node_id 2 for calling a global function with example usage: check_valid(s) and returns: unknown, False, False