from math import isqrt

N = int(input())
A = list(map(int, input().split()))

sum_A = sum(A)
A += [0] * (200 - N)
ans = float('inf')
for x in range(1, isqrt(sum_A) + 1):
    pyramid = [max(min(i + 1, 2 * x - i - 1), 0) for i in range(200)]
    diff = sum(abs(pyramid[i] - A[i]) for i in range(200))
    ans = min(ans, (diff + (sum_A - x ** 2)) // 2)
print(ans)