n = int(input())
cnt0, cnt1 = 0, 0
A = [int(input()) for _ in range(n)]
A.sort()
for a in A:
  if a % 2 == 0:
    cnt1 += 1
  else:
    cnt0 += 1
for i in range(n-1):
  if A[i+1] - A[i] <= 1:
    if cnt0 and cnt1:
      print(2)
      break
else:
  print(1)