def topView(root):
    if root.left:
        printleftside(root.left)
    print(root.info, end=' ')
    if root.right:
        printrightside(root.right)


def printleftside(node):
    if node:
        printleftside(node.left)
    else:
        return
    print(node.info, end=' ')


def printrightside(node):
    if node:
        print(node.info, end=' ')
        printrightside(node.right)
    else:
        return