mod = 998244353
n = int(input())
a = list(map(int,input().split()))
rui = a[::]
ans = 1
#for i in range(n-2,-1,-1):
#	rui[i] = min(rui[i], rui[i+1])
for i in range(n-1):
	ans *= min(a[i], a[i+1])
	ans %= mod
print(ans)