MOD = 998244353

def main():
    import sys
    input = sys.stdin.read().split()
    ptr = 0
    N = int(input[ptr])
    ptr += 1
    A = list(map(int, input[ptr:ptr+N]))
    ptr += N
    
    A = [a % MOD for a in A]
    
    total = 0
    for k in range(N):
        a_k = A[k]
        denominator = a_k
        for i in range(N):
            if i == k:
                continue
            a_i = A[i]
            term = (a_i * a_i - a_k * a_k) % MOD
            denominator = (denominator * term) % MOD
        # 计算 denominator 的逆元
        if denominator == 0:
            # 这种情况在问题中不存在，因为结果是有理数
            inv_den = 0
        else:
            inv_den = pow(denominator, MOD-2, MOD)
        total = (total + inv_den) % MOD
    print(total % MOD)

if __name__ == "__main__":
    main()