#include #include #include #include #include #include #include #include #include #include #include #include #include #define debug_value(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << #x << "=" << x << endl; #define debug(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << x << endl; template inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; } template inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; } using namespace std; typedef long long ll; template vector> vec2d(int n, int m, T v){ return vector>(n, vector(m, v)); } template vector>> vec3d(int n, int m, int k, T v){ return vector>>(n, vector>(m, vector(k, v))); } template void print_vector(vector v, char delimiter=' '){ if(v.empty()) { cout << endl; return; } for(int i = 0; i+1 < v.size(); i++) cout << v[i] << delimiter; cout << v.back() << endl; } template class Cumsum{ public: Cumsum(vector v): v(v){ n = v.size(); v_cumsum = vector(n+1, T(0)); for(int i = 0; i < n; i++) v_cumsum[i+1] = v_cumsum[i]+v[i]; } /** * v[l] + ... + v[r-1] */ T sum(int l, int r){ if(r <= l) return T(0); if(r > n) r = n; if(l < 0) l = 0; return v_cumsum[r]-v_cumsum[l]; } private: int n; vector v; vector v_cumsum; }; const int N = 200000; int main(){ ios::sync_with_stdio(false); cin.tie(0); cout << setprecision(10) << fixed; int n; cin >> n; vector a(n); vector cnt(N+1); vector sum(N+1); for(int i = 0; i < n; i++) { cin >> a[i]; cnt[a[i]]++; sum[a[i]] += a[i]; } auto cumsum = Cumsum(cnt); auto cumsum_all = Cumsum(sum); ll ans = 0; for(ll x = 1; x <= N; x++){ ll cnt_all = cumsum.sum(x+1, N+1); ll sum_all = cumsum_all.sum(x+1, N+1); ans += cnt[x]*(cnt_all*x - sum_all); for(ll i = 1; i*x <= N; i++){ int l = i*x, r = (i+1)*x; if(i == 1) l++; ll c = cumsum.sum(l, r); ans += cnt[x]*x*i*c; } } cout << ans << endl; }