Problem:
Score : 700 points

Problem Statement

We have an integer sequence of length N: A_0,A_1,\cdots,A_{N-1}.

Find the following sum (\mathrm{lcm}(a, b) denotes the least common multiple of a and b):

\sum_{i=0}^{N-2} \sum_{j=i+1}^{N-1} \mathrm{lcm}(A_i,A_j)

Since the answer may be enormous, compute it modulo 998244353.

Constraints

1 \leq N \leq 200000

1 \leq A_i \leq 1000000

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N
A_0\ A_1\ \cdots\ A_{N-1}

Output

Print the sum modulo 998244353.

Sample Input 1

3
2 4 6

Sample Output 1

22

\mathrm{lcm}(2,4)+\mathrm{lcm}(2,6)+\mathrm{lcm}(4,6)=4+6+12=22.

Sample Input 2

8
1 2 3 4 6 8 12 12

Sample Output 2

313

Sample Input 3

10
356822 296174 484500 710640 518322 888250 259161 609120 592348 713644

Sample Output 3

353891724

Solution in C++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <bits/stdc++.h>
#define whlie while
#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define rep(i,N) for(int i = 0; i < (N); i++)
#define repr(i,N) for(int i = (N) - 1; i >= 0; i--)
#define rep1(i,N) for(int i = 1; i <= (N) ; i++)
#define repr1(i,N) for(int i = (N) ; i > 0 ; i--)
#define each(x,v) for(auto& x : v)
#define all(v) (v).begin(),(v).end()
#define sz(v) ((int)(v).size())
#define vrep(v,it) for(auto it = v.begin(); it != v.end(); it++)
#define vrepr(v,it) for(auto it = v.rbegin(); it != v.rend(); it++)
#define ini(...) int __VA_ARGS__; in(__VA_ARGS__)
#define inl(...) ll __VA_ARGS__; in(__VA_ARGS__)
#define ins(...) string __VA_ARGS__; in(__VA_ARGS__)
using namespace std; void solve();
using ll = long long; using vl = vector<ll>;
using vi = vector<int>; using vvi = vector< vector<int> >;
constexpr int inf = 1001001001;
constexpr ll infLL = (1LL << 61) - 1;
struct IoSetupNya {IoSetupNya() { cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(15); cerr << fixed << setprecision(7);} } iosetupnya;
template<typename T, typename U> inline bool amin(T &x, U y) { return (y < x) ? (x = y, true) : false; }
template<typename T, typename U> inline bool amax(T &x, U y) { return (x < y) ? (x = y, true) : false; }
template<typename T, typename U> ostream& operator <<(ostream& os, const pair<T, U> &p) { os << p.first << " " << p.second; return os; }
template<typename T, typename U> istream& operator >>(istream& is, pair<T, U> &p) { is >> p.first >> p.second; return is; }
template<typename T> ostream& operator <<(ostream& os, const vector<T> &v) { int s = (int)v.size(); rep(i,s) os << (i ? " " : "") << v[i]; return os; }
template<typename T> istream& operator >>(istream& is, vector<T> &v) { for(auto &x : v) is >> x; return is; }
void in(){} template <typename T,class... U> void in(T &t,U &...u){ cin >> t; in(u...);}
void out(){cout << "\n";} template <typename T,class... U> void out(const T &t,const U &...u){ cout << t; if(sizeof...(u)) cout << " "; out(u...);}
template<typename T>void die(T x){out(x); exit(0);}
#ifdef NyaanDebug
  #include "NyaanDebug.h"
  #define trc(...) do { cerr << #__VA_ARGS__ << " = "; dbg_out(__VA_ARGS__);} while(0)
  #define trca(v,...) do { cerr << #v << " = "; array_out(v , __VA_ARGS__ );} while(0)
#else
  #define trc(...)
  #define trca(...)
  int main(){solve();}
#endif
 
using P = pair<ll,ll>; using vp = vector<P>;
constexpr int MOD = /** 1000000007; //*/ 998244353;
/////////////////

template<int N> struct invinit{
  long long inv[N + 1];
  constexpr invinit() : inv(){
    inv[0] = 0; inv[1] = 1;
    for(int i = 2; i <= N ; i++){
      inv[i] = MOD - inv[MOD % i] * (MOD / i) % MOD;
    }
  }
};

void solve(){
  constexpr int M = 1000000;
  constexpr auto inv = invinit<M>();
  rep(i,10) cout << inv.inv[i] << endl;
  vl mobius(M + 1);
  rep1(i , M) mobius[i] = inv.inv[i];
  for(int i = 2 ; i <= M ; i++){
    if(mobius[i] == inv.inv[i])
      for(int j = i ; j <= M; j += i){
        mobius[j] = mobius[j] * (1 + MOD - i) % MOD;
      }
  }
  ini(N); vl v(N); in(v); 
  vl cnt(M + 1 , 0); rep(i,N) cnt[v[i]]++;
  ll ans = 0;
  for(ll i = 1; i <= M ; i++){
    ll sum = 0 , sq_sum = 0;
    for(ll j = i ; j <= M ; j += i){
      if(cnt[j] == 0) continue;
      sum += cnt[j] * j;
      sq_sum += cnt[j] * j * j;
      sum %= MOD; sq_sum %= MOD;
    }
    if(sum == 0 && sq_sum == 0) continue;
    sum = sum * sum % MOD;
    sum = sum + MOD - sq_sum;
    if(sum >= MOD) sum -= MOD;
    if(sum % 2) sum = (sum + MOD) / 2;
    else sum = sum / 2;
    sum = sum * mobius[i] % MOD;
    ans += sum;
    if(ans >= MOD) ans -= MOD;
  }
  out(ans);

}