//#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
#define FOR(i, a, b) for(ll i = a; i < b; i++)
#define rep(i, n) FOR(i, 0, n)
#define rFOR(i, a, b) for(ll i = a - 1; i >= b; i--)
#define rrep(i, a) rFOR(i, a, 0)
#define pb push_back
using namespace std;
using ll = long long;
using ld = long double;
typedef pair<ll,ll> P;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<P> vP;
typedef vector<char> vc;
typedef vector<vc> vvc;
const ll MOD = 1000000007;
const ll MOD2 = 998244353;
const ld PI = acos(-1);
const ll INF = 1e18;
struct edge{ll to, cost;};

template <typename T>
bool chmax(T &a, const T &b) {
    if (a < b) {
      a = b;
        return true;
    }
    return false;
}

template <typename T>
bool chmin(T &a, const T &b) {
    if (a > b) {
      a = b;
      return true;
    }
    return false;
}

template< typename flow_t >
struct Dinic {
  const flow_t INF;

  struct edge {
    int to;
    flow_t cap;
    int rev;
    bool isrev;
    int idx;
  };

  vector< vector< edge > > graph;
  vector< int > min_cost, iter;

  Dinic(int V) : INF(numeric_limits< flow_t >::max()), graph(V) {}

  void add_edge(int from, int to, flow_t cap, int idx = -1) {
    graph[from].emplace_back((edge) {to, cap, (int) graph[to].size(), false, idx});
    graph[to].emplace_back((edge) {from, 0, (int) graph[from].size() - 1, true, idx});
  }

  bool bfs(int s, int t) {
    min_cost.assign(graph.size(), -1);
    queue< int > que;
    min_cost[s] = 0;
    que.push(s);
    while(!que.empty() && min_cost[t] == -1) {
      int p = que.front();
      que.pop();
      for(auto &e : graph[p]) {
        if(e.cap > 0 && min_cost[e.to] == -1) {
          min_cost[e.to] = min_cost[p] + 1;
          que.push(e.to);
        }
      }
    }
    return min_cost[t] != -1;
  }

  flow_t dfs(int idx, const int t, flow_t flow) {
    if(idx == t) return flow;
    for(int &i = iter[idx]; i < graph[idx].size(); i++) {
      edge &e = graph[idx][i];
      if(e.cap > 0 && min_cost[idx] < min_cost[e.to]) {
        flow_t d = dfs(e.to, t, min(flow, e.cap));
        if(d > 0) {
          e.cap -= d;
          graph[e.to][e.rev].cap += d;
          return d;
        }
      }
    }
    return 0;
  }

  flow_t max_flow(int s, int t) {
    flow_t flow = 0;
    while(bfs(s, t)) {
      iter.assign(graph.size(), 0);
      flow_t f = 0;
      while((f = dfs(s, t, INF)) > 0) flow += f;
    }
    return flow;
  }

  void output() {
    for(int i = 0; i < graph.size(); i++) {
      for(auto &e : graph[i]) {
        if(e.isrev) continue;
        auto &rev_e = graph[e.to][e.rev];
        cout << i << "->" << e.to << " (flow: " << rev_e.cap << "/" << e.cap + rev_e.cap << ")" << endl;
      }
    }
  }
};


int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int N;
    cin >> N;
    ll ans=0;
    Dinic<ll> D(N+2);
    int s=0,g=N+1;
    ll res=0;
    FOR(i,1,N+1){
        int a;
        cin >> a;
        if(a<=0){
            D.add_edge(s,i,-a);
        }
        else{
            res+=a;
            D.add_edge(i,g,a);
        }
        int j=2*i;
        while(j<=N){
            D.add_edge(i,j,INF);
            j+=i;
        }
    }
    //D.output();
    cout << res-D.max_flow(s,g) << '\n';
}
/*
overflow checked?
corner case checked?
boundary checked?
not TLE in worst case checked?
*/

Measured memory_bytes: 3676