#include <bits/stdc++.h>
using namespace std;

const int MM = 998244353;

long long modpow(long long a, long long n, long long mod) {
    long long res = 1;
    while (n > 0) {
        if (n & 1) res = res * a % mod;
        a = a * a % mod;
        n >>= 1;
    }
    return res;
}

long long modinv(long long a, long long mod) {
    return modpow(a, mod - 2, mod);
}

int main() {
  int N; cin >> N;
  vector<long long> A(N+1); for(int i=0;i<N;i++) cin >> A[i];

  long long ans=0;
  for (int i=0; i<N; i++) {
    long long ti1 = (A[i] * A[i]) % MM;
    long long quo=1;
    for (int j=0; j<N; j++) {
      if (j == i) continue;
      long long ti2 = (A[j] * A[j]) % MM;
      long long mm = ti1 - ti2;
      if (mm < 0) mm += MM;
      quo = (modinv(mm, MM) * quo) % MM;
    }
    long long mmod = (quo * modinv(A[i], MM)) % MM;
    ans = (ans + mmod) % MM;
  }
  if (N-1 % 2 == 1) ans += MM;
  cout << ans << endl;
}