#include <bits/stdc++.h>
using namespace std;
using lint = long long;
template<class T = int> using V = vector<T>;
template<class T = int> using VV = V< V<T> >;

template<unsigned P> struct ModInt {
  using M = ModInt;
  unsigned v;
  constexpr ModInt() : v(0) {}
  constexpr ModInt(auto x) : v(x >= 0 ? x % P : (P - -x % P) % P) {}
  constexpr ModInt(unsigned v, int) : v(v) {}
  static constexpr unsigned p() { return P; }
  M operator+() const { return *this; }
  M operator-() const { return {v ? P - v : 0, 0}; }
  explicit operator bool() const noexcept { return v; }
  bool operator!() const noexcept { return !(bool)*this; }
  M operator*(M r) const { return M(*this) *= r; }
  M operator/(M r) const { return M(*this) /= r; }
  M operator+(M r) const { return M(*this) += r; }
  M operator-(M r) const { return M(*this) -= r; }
  bool operator==(M r) const { return v == r.v; }
  bool operator!=(M r) const { return !(*this == r); }
  M& operator*=(M r) { v = (uint64_t)v * r.v % P; return *this; }
  M& operator/=(M r) { return *this *= r.inv(); }
  M& operator+=(M r) { if ((v += r.v) >= P) v -= P; return *this; }
  M& operator-=(M r) { if ((v += P - r.v) >= P) v -= P; return *this; }
  M inv() const {
    int a = v, b = P, x = 1, u = 0;
    while (b) {
      int q = a / b;
      swap(a -= q * b, b);
      swap(x -= q * u, u);
    }
    assert(a == 1);
    return x;
  }
  M pow(auto n) const {
    if (n < 0) return pow(-n).inv();
    M res = 1;
    for (M a = *this; n; a *= a, n >>= 1) if (n & 1) res *= a;
    return res;
  }
  friend M operator*(auto l, M r) { return M(l) *= r; }
  friend M operator/(auto l, M r) { return M(l) /= r; }
  friend M operator+(auto l, M r) { return M(l) += r; }
  friend M operator-(auto l, M r) { return M(l) -= r; }
  friend ostream& operator<<(ostream& os, M r) { return os << r.v; }
  friend istream& operator>>(istream& is, M& r) { lint x; is >> x; r = x; return is; }
  friend bool operator==(auto l, M r) { return M(l) == r; }
  friend bool operator!=(auto l, M r) { return !(l == r); }
};
using Mint = ModInt<998244353>;

V<> factor, mbs;
void init(int n) {
  factor.resize(n + 1, -1);
  iota(begin(factor) + 2, end(factor), 2);
  for (int p = 2; p * p <= n; ++p) if (factor[p] == p) {
    for (int i = p * p; i <= n; i += p) if (factor[i] == i) {
      factor[i] = p;
    }
  }
  mbs.resize(n + 1);
  mbs[1] = 1;
  for (int i = 2; i <= n; ++i) {
    if (factor[i] == factor[i / factor[i]]) mbs[i] = 0;
    else mbs[i] = -mbs[i / factor[i]];
  }
}

int main() {
  constexpr int U = 1e6;
  VV<> ds(U + 1);
  for (int d = 1; d <= U; ++d) {
    for (int i = d; i <= U; i += d) {
      ds[i].push_back(d);
    }
  }
  init(U);
  V<Mint> inv(U + 1);
  inv[1] = 1;
  for (int i = 2; i <= U; ++i) {
    int q = Mint::p() / i, r = Mint::p() - q * i;
    inv[i] = -q * inv[r];
  }

  cin.tie(nullptr); ios::sync_with_stdio(false);
  int n; cin >> n;
  V<Mint> s(U + 1);
  Mint res;
  while (n--) {
    int a; cin >> a;
    for (int d : ds[a]) {
      s[d] += a;
    }
    res -= a;
  }

  for (int x = 1; x <= U; ++x) {
    Mint c;
    for (int d : ds[x]) {
      c += mbs[x / d] * inv[d];
    }
    res += c * s[x] * s[x];
  }
  res /= 2;
  cout << res << '\n';
}

Measured memory_bytes: 130560