import math

n = int(input())

cf1 = 1.0
cfn = math.sqrt(1.0 - pow(0.81, n)) / ((1.0 - pow(0.9, n)) * math.sqrt(19))
cfinfty = 1 / math.sqrt(19)
fn = 1200 * (cfn - cfinfty) / (cf1 - cfinfty)

den = 9.0 * (1.0 - pow(0.9, n))
num = 0
ai = 1.0
for _ in range(n):
  rperf_i = int(input())
  ai *= 0.9
  num += pow(2.0, rperf_i / 800) * ai

ans = 800 * math.log(num / den, 2) - fn
print(round(ans))