class Node:
	def __init__(self,nodeValue):
		self.subNodes = []
		self.value = nodeValue

	def addSubNode(self,node):
		self.subNodes.append(node)

	def view(self,depth=0):
		if self.subNodes:
			print( "{}[{}]".format("  " * depth , self.value) )
		else:
			print("  " * depth , self.value)
		depth += 1
		for node in self.subNodes: 
            node.view(depth)