input: Write a python function to determine the largest power of 2 that does not exceed the provided number.
  assert largest_Power_of_2(10) == 8
  assert largest_Power_of_2(19) == 16
  assert largest_Power_of_2(32) == 32
output: def largest_Power_of_2(n):
      if n < 1:
          return 0
      power = 1
      while power * 2 <= n:
          power *= 2
      return power