mod=998244353 
n=int(input()) 
a = list(map(int, input().split())) 
place = [0 for i in range(n)]
for i in range(n) :
  place[a[i]] = i 
left = place[0] 
right = place[0]  
ans=1 
for i in range(n-1) :
  if place[i+1] < left :
    left = place[i+1] 
  elif place[i+1] > right :
    right = place[i+1] 
  else :
    ans=ans*(right-left-i) 
    ans%=mod

print(ans)