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

using ll = long long;
using ull = unsigned long long;
using ld = long double;
template<class t> using vc = vector<t>;
template<class t> using vvc = vc<vc<t>>;
using pi = pair<int,int>;
using vi = vc<int>;
using vvi = vvc<int>;

#define rep(i,a,b) for (int i = a; i < b; i++)
#define irep(i,a,b) for (int i = a; i > b; i--)
#define print(n) cout << n << endl
#define pritn(n) print(n)
#define rup(a,b) (a+b-1)/b
#define input(A,N) rep(i,0,N) cin>>A[i];


int main(){
    cout << fixed << setprecision(15);
    
    int N ;
    cin >> N;
    vc<ll> A(N);
    input(A,N);
    ll mod = 998244353;
    vvc<ll> dp(N,{0,0});
    map<ll,vc<ll>> d;
    rep(i,0,N){
        d[A[i]].push_back(i);
    }
    ll count = 0;
    rep(i,0,N){
        count += dp[i][0];
        count += dp[i][1];
        count %= mod;
        if (i==N-1) break;
        dp[i][0] ++;
        dp[i][1] ++;
        rep(j,0,d[A[i]+1].size()){
            dp[d[A[i]+1][j]][0] += dp[i][0];
            dp[d[A[i]+1][j]][0] %= mod;
        }
    }
    print(count);
    //system("pause");
    return 0;
}