mod = 998244353
N = int(input())
A = list(map(int, input().split()))

if max(A) != N:
  print(0)
  exit()

# 先頭がNになるようにスライド
B = []
while A[-1] != N:
  B.append(A.pop())
B.append(A.pop())
A = B[::-1] + A

# 操作するk
K = []
for k in range(N):
  if A[k] == N:
    K.append(k)

# 大きい順に決める.
ans = 1
for i in range(N - 1, 0, -1):
  c = 0
  for j in range(N):
    if A[j] == i:
      c += 1
  r = 0
  for j in range(1, N):
    cc = 0
    f = 1
    for k in K:
      if A[(j + k) % N] == i:
        cc += 1
      if A[(j + k) % N] < i:
        f = 0
    if f == 1 and c == cc:
      r += 1
  if c == 0:
    r -= (N - i - 1)
  ans = ans * r % mod
print(ans * N % mod)