#include <bits/stdc++.h>
using namespace std;
long long mod = 1000000007;
long long mod2 = 998244353;
long long mod3 = 1000003;
long long mod4 = 998244853;
long long mod5 = 1000000009;
long long inf = 1LL << 60;
double pi = 3.141592653589793238462643383279L;
double eps = 1e-9;
int dh[4] = {1, -1, 0, 0};
int dw[4] = {0, 0, 1, -1};
int ddh[8] = {-1, -1, -1, 0, 0, 1, 1, 1};
int ddw[8] = {-1, 0, 1, -1, 1, -1, 0, 1};
long long gcd(long long a, long long b) {
  if (a < b) swap(a, b);
  if (b == 0) return a;
  if (a % b == 0) return b;
  return gcd(b, a % b);
}
long long Pow(long long n, long long k) {
  long long ret = 1;
  long long now = n;
  while (k > 0) {
    if (k & 1) ret *= now;
    now *= now;
    k /= 2;
  }
  return ret;
}
long long beki(long long n, long long k, long long md) {
  long long ret = 1;
  long long now = n;
  while (k > 0) {
    if (k % 2 == 1) {
      ret *= now;
      ret %= md;
    }
    now *= now;
    now %= md;
    k /= 2;
  }
  return ret;
}
long long gyaku(long long n, long long md) { return beki(n, md - 2, md); }
long long popcount(long long n) {
  long long ret = 0;
  long long u = n;
  while (u > 0) {
    ret += u % 2;
    u /= 2;
  }
  return ret;
}
struct BIT {
 private:
  long long u;
  vector<long long> bit;

 public:
  BIT(long long n) {
    u = 1;
    while (u < n) u *= 2;
    bit.resize(u + 10, 0);
  }
  void add(long long n, long long x) {
    long long i = n;
    bit[i] += x;
    bit[i] %= mod;
    while (i < u) {
      i += i & (-i);
      bit[i] += x;
      bit[i] %= mod;
    }
  }
  long long sum(long long n) {
    long long i = n;
    long long ret = 0;
    while (i > 0) {
      ret += bit[i];
      i -= i & (-i);
      ret %= mod;
    }
    return ret;
  }
};
long long gya[1000010];
long long kai[1000010];
void nckinit(long long n, long long md) {
  kai[0] = 1;
  kai[1] = 1;
  for (int i = 2; i <= n; i++) {
    kai[i] = kai[i - 1] * i;
    kai[i] %= md;
  }
  gya[n] = gyaku(kai[n], md);
  for (int i = n - 1; i >= 1; i--) {
    gya[i] = gya[i + 1] * (i + 1);
    gya[i] %= md;
  }
  gya[0] = 1;
}
long long nck(long long n, long long k, long long md) {
  if (k < 0) return 0;
  if (k == 0 || n == k) return 1;
  long long ret = kai[n];
  ret *= gya[n - k];
  ret %= md;
  ret *= gya[k];
  ret %= md;
  return ret;
}
long long npk(long long n, long long k, long long md) {
  if (k < 0) return 0;
  if (k == 0) return 1;
  long long ret = kai[n];
  ret *= gya[n - k];
  ret %= md;
  return ret;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long n;
  cin >> n;
  long long p[n];
  long long l = 0;
  bool used[n + 1];
  fill(used, used + n + 1, false);
  long long pla[n + 1];
  for (long long i = 0; i < n; i++) {
    cin >> p[i];
    if (p[i] == -1)
      l++;
    else {
      used[p[i]] = true;
      pla[p[i]] = i + 1;
    }
  }
  long long dp[l + 1];
  dp[0] = 0;
  dp[1] = 0;
  nckinit(n + 1, mod2);
  for (long long i = 2; i < l + 1; i++) {
    dp[i] = i * (i - 1) / 2;
    dp[i] %= mod2;
    (dp[i] *= kai[i - 1]) %= mod2;
    (dp[i] += dp[i - 1] * i) %= mod2;
  }
  long long su[n + 1];
  su[n] = 0;
  for (long long i = n - 1; i >= 0; i--) {
    su[i] = su[i + 1];
    if (p[i] == -1) su[i]++;
  }
  long long cnt = 0;
  BIT bit(n + 1);
  long long ans = dp[l];
  for (long long i = n; i >= 1; i--) {
    if (used[i]) {
      long long r = bit.sum(pla[i]);
      (ans += r * kai[l]) %= mod2;
      bit.add(pla[i], 1);
      cnt += su[pla[i] - 1];
      cnt %= mod2;
    } else {
      (ans += cnt * kai[l - 1]) %= mod2;
    }
  }
  long long su2[n + 1];
  su2[0] = 0;
  for (long long i = 0; i < n; i++) {
    su2[i + 1] = su2[i];
    if (p[i] == -1) su2[i + 1]++;
  }
  cnt = 0;
  for (long long i = 1; i < n + 1; i++) {
    if (used[i]) {
      cnt += su2[pla[i]];
      cnt %= mod2;
    } else {
      (ans += cnt * kai[l - 1]) %= mod2;
    }
  }
  ans *= gya[l];
  cout << ans % mod2 << endl;
}
