#include <bits/stdc++.h>
#define FOR(i, begin, end) for(int i=(begin);i<(end);i++)
#define REP(i, n) FOR(i,0,n)
#define IFOR(i, begin, end) for(int i=(end)-1;i>=(begin);i--)
#define IREP(i, n) IFOR(i,0,n)
#define SORT(a) sort(a.begin(), a.end())
#define REVERSE(a) reverse(a.begin(), a.end())
#define Lower_bound(v, x) distance(v.begin(), lower_bound(v.begin(), v.end(), x))
#define Upper_bound(v, x) distance(v.begin(), upper_bound(v.begin(), v.end(), x))
#define int long long
#define INF 1000000000000000000
using namespace std;

#define ANS(f) if(f) cout << "YES" << endl; else cout << "NO" << endl;

typedef vector<int> vec;
typedef vector<vec> mat;
typedef pair<int, int> Pii;

template<typename T>
void readv(vector<T> &a){ REP(i, a.size()) cin >> a[i]; }
void readi(vector<int> &a){ REP(i, a.size()){cin >> a[i]; a[i]--;} }
void debug(mat m){REP(i, m.size()){ REP(j, m[i].size()){ cout << m[i][j] << ","; } cout << endl; }}

struct edge { int to, cap, rev; };

class Graph
{
public:
    int N;
    vector<vector<edge>> G;
    vec level, iter;

    Graph(int N): N(N){
        G = vector<vector<edge>>(N, vector<edge>(0));
        level = vec(N);
        iter = vec(N);
    }

    void add_edge(int from, int to, int cap){
        G[from].push_back((edge){to, cap, G[to].size()});
        G[to].push_back((edge){from, 0, G[from].size() - 1});
    }

    void bfs(int s){
        memset(&level[0], -1, sizeof(level[0]) * level.size());
        queue<int> que;
        level[s] = 0;
        que.push(s);
        while(!que.empty()){
            int v = que.front(); que.pop();
            REP(i, G[v].size()){
                edge &e = G[v][i];
                if(e.cap > 0 && level[e.to] < 0){
                    level[e.to] = level[v] + 1;
                    que.push(e.to);
                }
            }
        }
    }

    int dfs(int v, int t, int f){
        if(v == t) return f;
        for(int &i = iter[v]; i < G[v].size(); i++){
            edge &e = G[v][i];
            if(e.cap > 0 && level[v] < level[e.to]){
                int d = dfs(e.to, t, min(f, e.cap));
                if(d > 0){
                    e.cap -= d;
                    G[e.to][e.rev].cap += d;
                    return d;
                }
            }
        }
        return 0;
    }

    int max_flow(int s, int t){
        int flow = 0;
        for(;;){
            bfs(s);
            if(level[t] < 0) return flow;
            memset(&iter[0], 0, sizeof(iter[0]) * iter.size());
            int f;
            while((f = dfs(s, t, INF)) > 0) flow += f;
        }
    }

};


signed main(){

    int N;
    cin >> N;
    vector<int> a(N + 1);
    int psum = 0;
    REP(i, N){
        cin >> a[i + 1];
        psum += max((int)0, a[i + 1]);
    }

    Graph G(N + 2);
    int s = 0, t = N + 1;

    FOR(i, 1, N + 1){
        if(a[i] >= 0){
            //割ることで生じる損失
            G.add_edge(i, t, a[i]);
        }else{
            //割らないことで生じる損失
            G.add_edge(s, i, -1 * a[i]);
        }
        for(int j = i + i; j <= N; j += i){
            G.add_edge(i, j, INF);
        }
    }

    int mincut = G.max_flow(s, t);

    int ans = psum - mincut;

    cout << ans;

    return 0;
}


Measured memory_bytes: 256