/**
	author:  shobonvip
	created: 2024.10.25 22:03:11
**/

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

//* ATCODER
#include<atcoder/all>
using namespace atcoder;
typedef modint998244353 mint;
//*/

/* BOOST MULTIPRECISION
#include<boost/multiprecision/cpp_int.hpp>
using namespace boost::multiprecision;
//*/

typedef long long ll;

#define rep(i, s, n) for (int i = (int)(s); i < (int)(n); i++)
#define rrep(i, s, n) for (int i = (int)(n)-1; i >= (int)(s); i--)

template <typename T> bool chmin(T &a, const T &b) {
	if (a <= b) return false;
	a = b;
	return true;
}

template <typename T> bool chmax(T &a, const T &b) {
	if (a >= b) return false;
	a = b;
	return true;
}

template <typename T> T max(vector<T> &a){
	assert(!a.empty());
	T ret = a[0];
	for (int i=0; i<(int)a.size(); i++) chmax(ret, a[i]);
	return ret;
}

template <typename T> T min(vector<T> &a){
	assert(!a.empty());
	T ret = a[0];
	for (int i=0; i<(int)a.size(); i++) chmin(ret, a[i]);
	return ret;
}

template <typename T> T sum(vector<T> &a){
	T ret = 0;
	for (int i=0; i<(int)a.size(); i++) ret += a[i];
	return ret;
}


struct S{
	mint val;
	ll len;
};

struct F{
	mint b;
	mint c;
};

S op(S x, S y){
	return {x.val + y.val, x.len + y.len};
}

S e(){
	return {0, 0};
}

S mapping(F f, S x){
	return {f.b * x.val + f.c * x.len, x.len};
}

F composition(F g, F f){
	return {f.b * g.b, f.c * g.b + g.c};
}

F id(){
	return {1, 0};
}

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	
	int n; cin >> n;
	vector<ll> a(n);
	rep(i,0,n){
		cin >> a[i];
	}

	vector<int> max_st = {(int)1e9+20};
	vector<int> max_ind = {0};
	vector<int> min_st = {-1};
	vector<int> min_ind = {0};

	multiset<pair<int,int>> bad_points;
	lazy_segtree<S,op,e,F,mapping,composition,id> seg(vector<S>(n,S{1,1}));

	mint ans = 0;
	rep(i,0,n){
		{
			int now = i;
			while(a[i] >= max_st.back()) {
				int val = max_st.back();
				max_ind.pop_back();
				int tar = max_ind.back();
				if (val == 998244353){
					bad_points.erase(bad_points.find(pair(tar, now)));
				}else{
					seg.apply(tar, now, F{mint(val).inv(), 0});
				}
				max_st.pop_back();
				now = tar;
			}
			if (a[i] == 998244353){
				bad_points.insert(pair(now, i+1));
			}else{
				seg.apply(now, i+1, F{a[i], 0});
			}
			max_st.push_back(a[i]);
			max_ind.push_back(i+1);
		}
		
		{
			int now = i;
			while(a[i] <= min_st.back()) {
				int val = min_st.back();
				min_ind.pop_back();
				int tar = min_ind.back();
				if (val == 998244353){
					bad_points.erase(bad_points.find(pair(tar, now)));
				}else{
					seg.apply(tar, now, F{mint(val).inv(), 0});
				}
				min_st.pop_back();
				now = tar;
			}
			if (a[i] == 998244353){
				bad_points.insert(pair(now, i+1));
			}else{
				seg.apply(now, i+1, F{a[i], 0});
			}
			min_st.push_back(a[i]);
			min_ind.push_back(i+1);
		}

		vector<int> v = {0, i+1};
		for(auto [l,r]: bad_points){
			v.push_back(l);
			v.push_back(r);
		}
		sort(v.begin(), v.end());

		vector<int> imos((int)v.size());
		for(auto [l,r]: bad_points){
			imos[lower_bound(v.begin(), v.end(), l) - v.begin()] += 1;
			imos[lower_bound(v.begin(), v.end(), r) - v.begin()] -= 1;
		}

		rep(j,0,(int)v.size()-1){
			imos[j+1] += imos[j];
		}
		rep(j,0,(int)v.size()-1){
			if (imos[j] == 0){
				ans += seg.prod(v[j], v[j+1]).val;
			}
		}
	}	
	cout << ans.val() << '\n';
}