MOD = 998244353

n = int(input())
a = list(map(int, input().split()))

a_squared = [(x * x) % MOD for x in a]

sum_result = 0

for i in range(n):
    product = 1
    ai_sq = a_squared[i]
    ai = a[i]
    for k in range(n):
        if k != i:
            term = (a_squared[k] - ai_sq) % MOD
            product = (product * term) % MOD
    denominator = (ai * product) % MOD
    inv_denominator = pow(denominator, MOD - 2, MOD)
    sum_result = (sum_result + inv_denominator) % MOD

print(sum_result)