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# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

from extratypes import Tree  # library with types used in the task

def visableNum(T, currentMax = 0):
    if T == None:
        return 0
    count = 0
    if T.x >= currentMax:
        count = 1
        currentMax = T.x
    return count + visableNum(T.l, currentMax) + visableNum(T.r, currentMax)

def solution(T):
    # write your code in Python 3.6
    return visableNum(T)
    pass