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

X = [-1]*N
for i in range(N):
    
    X[P[i]] = i
    
L = min(X[0:2])
R = max(X[0:2])
ans = 1
for i in range(2,N):
    
    
    tX = X[i]
    if L<tX<R:
        ans *= (R-L-i+1)
        ans %= mod
    else:
        L = min(L,tX)
        R = max(R,tX)
    
print(ans)