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We have a list of tasks to perform, with a cooldown period. We can do multiple of these at the same time, but we cannot run the same task simultaneously.

Given a list of tasks, find how long it will take to complete the tasks in the order they are input.

tasks = [1, 1, 2, 1]
cooldown = 2
output: 7 (order is 1 _ _ 1 2 _ 1)

def findTime(arr, cooldown):
  # Fill this in.

print findTime([1, 1, 2, 1], 2)
# 7