code: def ack1(M, N):
      return (
          (N + 1)
          if M == 0
          else (
              ack1(M - 1, 1) if N == 0 else ack1(M - 1, ack1(M, N - 1))
          )
      )
  
label_desc: Use image node_id 1 for calling a global function with example usage: ack1(M, N) and returns: unknown