#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
using ll=long long;
#define rep(i,n) for(int i=0;i<n;i++)
#define rrep(i,n) for(int i=(n)-1;i>=0;i--)
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
template<class T> bool chmax(T &a, T b){if (a < b){a = b;return true;} else return false;}
template<class T> bool chmin(T &a, T b){if (a > b){a = b;return true;} else return false;}

const ll MOD=998244353;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n;
    cin>>n;
    vector<ll>A(n);
    rep(i,n)cin>>A[i];
    ll ans=1;
    rep(i,n-1){
        ans*=min(A[i],A[i+1]);
        ans%=MOD;
    }
    cout<<ans<<"\n";
}