import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#######################################################################
n = ni()
a = na()
mod = 998244353
ans = 1

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