#include <bits/stdc++.h>
#define FOR(i, a, n) for(ll i = (ll)a; i < (ll)n; i++)
#define FORR(i, n) for(ll i = (ll)n - 1LL; i >= 0LL; i--)
#define rep(i, n) FOR(i, 0, n)
#define ALL(x) begin(x), end(x)
using namespace std;
using ll = long long;
constexpr ll Mod = 998244353;
constexpr ll mod = 1e9 + 7;
constexpr ll inf = 1LL << 60;
const double PI = acos(-1);
template <typename T> constexpr bool chmax(T &a, const T &b) {
    if(a >= b) return false;
    a = b;
    return true;
}
template <typename T> constexpr bool chmin(T &a, const T &b) {
    if(a <= b) return false;
    a = b;
    return true;
}

/*-------------------------------------------*/

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() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    int n;
    cin >> n;
    Dinic<ll> G(n + 2);

    ll ans = 0;

    FOR(i, 1, n + 1) {
        ll a;
        cin >> a;
        if(a <= 0)
            G.add_edge(0, i, -a);
        else {
            G.add_edge(i, n + 1, a);
            ans += a;
        }
        for(int j = i + i; j <= n; j += i)
            G.add_edge(i, j, G.INF);
    }

    cout << ans - G.max_flow(0, n + 1) << endl;

    return 0;
}

Measured memory_bytes: 256