N=int(input())
P=list(map(int,input().split()))
pos=[0]*N
for i in range(N):
    pos[P[i]]=i
lf=pos[0]
ri=pos[0]
ans=1
for i in range(1,N):
    if pos[i]<lf:
        lf=pos[i]
    elif ri<pos[i]:
        ri=pos[i]
    else:
        ans*=(ri-lf+1-i)
        ans%=998244353
print(ans)