#include <stdio.h>
#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000001
#define Inf64 4000000000000000001LL
struct combi{
	deque<mint> kaijou;
	deque<mint> kaijou_;
	
	combi(int n){
		kaijou.push_back(1);
		for(int i=1;i<=n;i++){
			kaijou.push_back(kaijou[i-1]*i);
		}
		
		mint b=kaijou[n].inv();
		
		kaijou_.push_front(b);
		for(int i=1;i<=n;i++){
			int k=n+1-i;
			kaijou_.push_front(kaijou_[0]*k);
		}
	}
	
	mint combination(int n,int r){
		if(r>n)return 0;
		mint a = kaijou[n]*kaijou_[r];
		a *= kaijou_[n-r];
		return a;
	}
	
	mint junretsu(int a,int b){
		mint x = kaijou_[a]*kaijou_[b];
		x *= kaijou[a+b];
		return x;
	}
	
	mint catalan(int n){
		return combination(2*n,n)/(n+1);
	}
	
};
combi C(4000000);
int main(){
	
	int n;
	cin>>n;
	vector<int> a(n);
	vector<int> pos(n,-1);
	rep(i,n){
		cin>>a[i];
		if(a[i]>0){
			a[i]--;
			pos[a[i]] = i;
		}
	}
	vector<int> cnt(n+1);
	rep(i,n){
		if(a[i]==-1)cnt[i+1] = 1;
		cnt[i+1] += cnt[i];
	}
	int larger = 0;
	int all = cnt.back();
	mint ans = 0;
	int minpos = n;
	for(int i=n-1;i>=0;i--){
		if(pos[i]!=-1){
			if(minpos<pos[i]){
				ans += C.kaijou[all];
				continue;
			}
			
			int Suf = cnt[n]-cnt[pos[i]];
			int Pre = cnt[pos[i]];
			ans += C.kaijou[all];
			ans -= C.combination(Suf, larger) * C.kaijou[larger] * C.kaijou[all-larger];
			minpos = min(minpos,pos[i]);
		}
		else{
			mint t = C.kaijou[all] / (larger+1);
			ans += t * (larger);
			int Pre = cnt[minpos];
			int Suf = cnt[n]-cnt[minpos];
			larger++;
			t = C.combination(Suf, larger) * C.kaijou[larger] * C.kaijou[all-larger];
			t /= larger;
			ans += t;
		}
		
	}
	mint t = C.kaijou[all] * n;
	t -= ans;
	cout<<t.val()<<endl;
	return 0;
}