#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 1000000000000000001

int main(){
	
	int n;
	cin>>n;
	
	vector c(9,0);
	rep(i,n){
		int a;
		cin>>a;
		c[a] ++;
	}
	mint ans = 0;
	rep(i,9){
		rep(j,9){
			mint t = mint(i).pow(j);
			t *= c[i];
			t *= c[j];
			ans += t;
			
		}
	}
	cout<<ans.val()<<endl;
	
	return 0;
}