from collections import defaultdict
import sys
readline=sys.stdin.readline

N=int(readline())
P=list(map(int,readline().split()))
idx=[None]*N
for i in range(N):
    idx[P[i]]=i
used=[False]*N
lst=[]
ans=1
mod=998244353
a,b=idx[0],idx[0]+1
for i in range(1,N):
    if idx[i]<a:
        a=idx[i]
    elif b<=idx[i]:
        b=idx[i]+1
    else:
        ans*=b-a-i
        ans%=mod
print(ans)