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

#include<atcoder/all>
using namespace atcoder;

using mint=atcoder::modint998244353;

struct S{
	mint sum;
	int len;
};

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

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

S mapping(int f,S x){
	if(f==-1)return x;
	else return {mint(f)*x.len,x.len};
}

int composition(int f,int g){
	if(f==-1)return g;
	else return f;
}

int id(){
	return -1;
}

int main(){
	int n;cin>>n;
	vector<int> a(n);for(auto&e:a)cin>>e;
	stack<tuple<int,int,int>> inc,dec;
	lazy_segtree<S,op,e,int,mapping,composition,id> seg_inc(vector<S>(n,{0,1}));
	lazy_segtree<S,op,e,int,mapping,composition,id> seg_dec(vector<S>(n,{0,1}));
	mint ans=0,sum=0;
	for(int i=0;i<n;i++){
		int incl=i;
		while(inc.size()&&get<0>(inc.top())<=a[i]){
			auto[v,l,r]=inc.top();
			incl=l;
			sum-=mint(v)*seg_dec.prod(l,r).sum;
			inc.pop();
		}
		inc.push({a[i],incl,i+1});
		sum+=mint(a[i])*seg_dec.prod(incl,i+1).sum;
		seg_inc.apply(incl,i+1,a[i]);
		int decl=i;
		while(dec.size()&&get<0>(dec.top())>=a[i]){
			auto[v,l,r]=dec.top();
			decl=l;
			sum-=mint(v)*seg_inc.prod(l,r).sum;
			dec.pop();
		}
		dec.push({a[i],decl,i+1});
		sum+=mint(a[i])*seg_inc.prod(decl,i+1).sum;
		seg_dec.apply(decl,i+1,a[i]);
		ans+=sum;
	}
	cout<<ans.val()<<endl;
}