mod = 998244353

def main():
    import sys
    input = sys.stdin.read().split()
    N = int(input[0])
    A = list(map(int, input[1:N+1]))
    
    sum_I = 0
    for j in range(N):
        a_j = A[j]
        D_j = 1
        for i in range(N):
            if i == j:
                continue
            a_i = A[i]
            term = (a_i * a_i - a_j * a_j) % mod
            D_j = (D_j * term) % mod
        # Compute inverse of D_j
        inv_Dj = pow(D_j, mod-2, mod)
        inv_Aj = pow(a_j, mod-2, mod)
        T_j = (inv_Aj * inv_Dj) % mod
        sum_I = (sum_I + T_j) % mod
    print(sum_I % mod)

if __name__ == '__main__':
    main()