mod_val = 998244353

N = int(input())
A = list(map(int, input().split()))

a_mods = []
a_sq_mods = []
for a in A:
    a_mod = a % mod_val
    a_mods.append(a_mod)
    a_sq_mod = (a_mod * a_mod) % mod_val
    a_sq_mods.append(a_sq_mod)

sum_result = 0

for k in range(N):
    a_k_sq = a_sq_mods[k]
    D_k = 1
    for j in range(N):
        if j == k:
            continue
        a_j_sq = a_sq_mods[j]
        diff = (a_j_sq - a_k_sq) % mod_val
        D_k = (D_k * diff) % mod_val
    inv_Dk = pow(D_k, mod_val - 2, mod_val)
    a_k_mod = a_mods[k]
    inv_ak = pow(a_k_mod, mod_val - 2, mod_val)
    term_k = (inv_ak * inv_Dk) % mod_val
    sum_result = (sum_result + term_k) % mod_val

print(sum_result)