#include <bits/stdc++.h>
using namespace std;
const long long MOD = 998244353;
long long pwr(long long a, long long b) {
  long long ans = 1;
  while (b) {
    if (b & 1) ans = ans * a % MOD;
    b >>= 1, a = a * a % MOD;
  }
  return ans;
}
long long inv(long long a) { return pwr(a, MOD - 2); }
template <class T, int SZ>
struct BIT {
  T bit[SZ + 1];
  BIT() { memset(bit, 0, sizeof bit); }
  void upd(int k, T val) {
    for (; k <= SZ; k += (k & -k)) bit[k] += val;
  }
  T query(int k) {
    T temp = 0;
    for (; k > 0; k -= (k & -k)) temp += bit[k];
    return temp;
  }
  T query(int l, int r) { return query(r) - query(l - 1); }
};
BIT<long long, 1 << 18> b1;
BIT<long long, 1 << 18> b2;
map<int, bool> m;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long n, cnt = 0, ans = 0, k;
  cin >> n;
  long long a[n];
  for (int i = 0; i < n; ++i) {
    cin >> a[i];
    if (a[i] == -1)
      ++cnt;
    else {
      m[a[i]] = 1;
    }
  }
  ans += ((cnt * (cnt - 1)) % MOD * inv((long long)4)) % MOD;
  for (int i = 0; i < n; ++i) {
    if (a[i] != -1) {
      b1.upd(a[i], 1LL);
      ans += b1.query(a[i] + 1, n);
      ans %= MOD;
    }
  }
  for (int i = 1; i <= n; ++i) {
    if (!m[i]) b2.upd(i, 1LL);
  }
  long long left[n], right[n], t = 0;
  for (int i = 0; i < n; ++i) {
    left[i] = t;
    t += (a[i] == -1);
  }
  t = 0;
  for (int i = n - 1; i >= 0; --i) {
    right[i] = t;
    t += (a[i] == -1);
  }
  for (int i = 0; i < n; ++i) {
    if (a[i] != -1) {
      k = (left[i] * b2.query(a[i], n)) % MOD;
      k = (k * inv(cnt)) % MOD;
      ans += k;
      k = (right[i] * b2.query(1, a[i])) % MOD;
      k = (k * inv(cnt)) % MOD;
      ans += k;
      ans %= MOD;
    }
  }
  cout << ans % MOD << '\n';
  return 0;
}
