#include<algorithm>
#include<cmath>
#include<iomanip>
#include<iostream>
#include<map>
#include<numeric>
#include<queue>
#include<set>
#include<sstream>
#include<unordered_map>
#include<unordered_set>
#include<vector>
using uint = unsigned int;
using ll = long long;
enum : int { M = (int)1e9 + 7 };
enum : ll { MLL = (ll)1e18L + 9 };
using namespace std;
#ifdef LOCAL
#include"rprint2.hpp"
#include"debug_deque.hpp"
#define vector DebugDeque
#else
#define FUNC(name) template <ostream& out = cout, class... T> void name(T&&...){ }
FUNC(prints) FUNC(printe) FUNC(printw) FUNC(printew) FUNC(printb) FUNC(printd) FUNC(printde);
#endif

struct Graph{
    struct Node;
    struct Edge{
        // Node *from, *to;
        int from, to;
        ll limit, rem;
        Edge(){ }
        // Edge(Node* from, Node* to, ll limit = 1): from(from), to(to), limit(limit), rem(limit){ }
        Edge(int from, int to, ll limit = 1): from(from), to(to), limit(limit), rem(limit){ }
        ll remain(bool rev = false){
            return rev ? limit - rem : rem;
        }
        void pour(ll f, bool rev = false){
            rem -= rev ? - f : f;
        }
    };
    // int numNodes = 0;
    struct Node{
        // int id;
        // vector<Edge*> inEdges, outEdges;
        vector<int> inEdges, outEdges;
        // Node(): id(numNodes++){ }
        // Edge* add(Edge* e){
        //     outEdges.push_back(e);
        //     e->to->inEdges.push_back(e);
        //     return e;
        // }
    };
        void addEdge(int from, int dest, ll limit){
            nodes[from].outEdges.emplace_back(edges.size());
            nodes[dest].inEdges.emplace_back(edges.size());
            edges.emplace_back(from, dest, limit);
        }
    vector<Node> nodes;
    vector<Edge> edges;
    Graph(int nn, int en = 10): nodes(nn){
        edges.reserve(en);
    }
    // ll flow(Node* start, Node* goal, vector<char>& visited, ll cur){
    ll flow(int start, int goal, vector<char>& visited, ll cur){
        if(start == goal){ return cur; }
        // auto _flow = [&](Node* Edge::* to, vector<Edge*> Node::* edges, bool rev = false){
        auto _flow = [&](int Edge::* to, vector<int> Node::* es, bool rev = false){
            for(int ei : nodes[start].*es){
                Edge& e = edges[ei];
                int vidx = e.*to;
                if(!e.remain(rev) || visited[vidx]){ continue; }
                visited[vidx] = true;
                ll lim = min(cur, e.remain(rev));
                if((lim = flow(vidx, goal, visited, lim))){
                    e.pour(lim, rev);
                    return lim;
                }
            }
            return 0ll;
        };
        ll ret = 0;
        if((ret = _flow(&Edge::to, &Node::outEdges)) ||
           (ret = _flow(&Edge::from, &Node::inEdges, true))){
            return ret;
        }
        return ret;
    }
    // ll maxFlow(Node* start, Node* goal){
    ll maxFlow(int start, int goal){
        if(start == goal){ exit(1); }
        ll ret = 0;
        while(1){
            vector<char> visited(nodes.size());
            ll f;
            if(!(f = flow(start, goal, visited, MLL))){
                break;
            }
            ret += f;
        }
        return ret;
    }
};

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n; cin >> n;
    Graph g(n + 2, 2 * n);
    // vector<Node> nodes(n + 1);
    // Node sn, tn;
    // vector<Edge> edges(10 * n);
    // int eidx = 0;
    ll sum = 0;
    for(int i = 1; i <= n; i++){
        int a; cin >> a;
        if(a > 0){
            sum += a;
            // edges[eidx] = Edge(&nodes[i], &tn, a);
            // nodes[i].add(&edges[eidx]);
            // eidx++;
            g.addEdge(i, n + 1, a);
        }else{
            // edges[eidx] = Edge(&sn, &nodes[i], - a);
            // sn.add(&edges[eidx]);
            // eidx++;
            g.addEdge(0, i, - a);
        }
    }
    for(int i = 1; i <= n; i++){
        for(int j = i + i; j <= n; j += i){
            // edges[eidx] = Edge(&nodes[i], &nodes[j], MLL);
            // nodes[i].add(&edges[eidx]);
            // eidx++;
            g.addEdge(i, j, MLL);
        }
    }
    // ll mi = maxFlow(&sn, &tn);
    ll mi = g.maxFlow(0, n + 1);
    cout << sum - mi << '\n';
}


Measured memory_bytes: 256