MOD = 998244353

def main():
    import sys
    input = sys.stdin.read().split()
    N = int(input[0])
    A = list(map(int, input[1:N+1]))
    
    sum_terms = 0
    for j in range(N):
        aj = A[j]
        product = 1
        for k in range(N):
            if k == j:
                continue
            ak = A[k]
            denominator = (ak * ak - aj * aj) % MOD
            if denominator == 0:
                product = 0
                break
            product = (product * denominator) % MOD
        if product == 0:
            continue
        inv_product = pow(product, MOD-2, MOD)
        inv_aj = pow(aj, MOD-2, MOD)
        term = (inv_aj * inv_product) % MOD
        sum_terms = (sum_terms + term) % MOD
    print(sum_terms % MOD)

if __name__ == '__main__':
    main()