#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 mobiusinit{
  long long inv[N + 1] , mobius[N + 1];
  constexpr mobiusinit() : inv() , mobius() {
    inv[0] = 0; inv[1] = 1;
    for(int i = 2; i <= N ; i++){
      inv[i] = MOD - inv[MOD % i] * (MOD / i) % MOD;
    }
    for(int i = 0; i <= N ; i++) mobius[i] = inv[i];
    for(int i = 2; i <= N ; i++){
      if(mobius[i] == inv[i])
        for(int j = i; j <= N; j += i)
          mobius[j] = mobius[j] * (1 + MOD - i) % MOD;
    } 
  }
  const long long& operator[](long long i) const{return mobius[i];}
};

void solve(){
  constexpr int M = 1000000;
  constexpr auto mobius = mobiusinit<M>();
  //rep(i,10) cout << inv.inv[i] << endl;
  ini(N); vl v(N); in(v); 
  vl cnt(M + 1 , 0); rep(i,N) cnt[v[i]]++;
  vl sum(M + 1 , 0);
  rep1(i,M) {
    if(cnt[i]) sum[i] = cnt[i] * i % MOD;
  }
  vector<bool> sieve(M + 1 , true);
  for(int p = 2; p <= M; p++){
    if(sieve[p]){
      for(int k = M / p; k > 0; k--){
        sieve[k * p] = false;
        sum[k] += sum[k * p];
        if(sum[k] >= MOD) sum[k] -= MOD;
      }
    }
  }
  rep(i,10) trc(i , mobius[i] , sum[i] );
  ll ans = 0;
  for(int i = 1; i <= M ; i++){
    if(sum[i] == 0) continue;
    ll cur = sum[i] * sum[i] % MOD * mobius[i] % MOD;
    ans += cur;
  }
  ans %= MOD;
  trc(ans);
  //　引く
  rep(i,N) ans -= v[i];
  ans %= MOD; if(ans < 0) ans += MOD;
  if(ans & 1) ans = (ans + MOD) / 2;
  else ans = ans / 2;
  out(ans);

}


Measured memory_bytes: 33152