input: def isSubTree(T: Node, S: Node) -> bool:
      """ Check if the given binary tree S is a subtree of binary tree T.
      
      >>> T1 = Node(1)
      >>> T1.left = Node(2)
      >>> T1.right = Node(3)
      >>> T2 = Node(1)
      >>> T2.left = Node(2)
      >>> T2.right = Node(4)
      >>> isSubTree(T1, T2)
      False
      >>> T3 = Node(2)
      >>> T3.left = Node(3)
      >>> isSubTree(T1, T3)
      False
      """
output:     if not T and not S:
          return True
      if not T or not S:
          return False
      if T.value == S.value:
          return isSubTree(T.left, S.left) and isSubTree(T.right, S.right)
      return isSubTree(T.left, S) or isSubTree(T.right, S)