import sys
from collections import deque, Counter
input = lambda: sys.stdin.readline().rstrip()
ii = lambda: int(input())
mi = lambda: map(int, input().split())
li = lambda: list(mi())
inf = 2 ** 63 - 1
mod = 998244353

n = ii()
a = li()
ans = 1

for i in range(n - 1):
    ans *= min(a[i], a[i + 1])
    ans %= mod
print(ans)