#include <bits/stdc++.h>

#define _overload(_1,_2,_3,name,...) name
#define _rep(i,n) _range(i,0,n)
#define _range(i,a,b) for(int i=int(a);i<int(b);++i)
#define rep(...) _overload(__VA_ARGS__,_range,_rep,)(__VA_ARGS__)

#define _rrep(i,n) _rrange(i,n,0)
#define _rrange(i,a,b) for(int i=int(a)-1;i>=int(b);--i)
#define rrep(...) _overload(__VA_ARGS__,_rrange,_rrep,)(__VA_ARGS__)

#define _all(arg) begin(arg),end(arg)
#define uniq(arg) sort(_all(arg)),(arg).erase(unique(_all(arg)),end(arg))
#define getidx(ary,key) lower_bound(_all(ary),key)-begin(ary)
#define clr(a,b) memset((a),(b),sizeof(a))
#define bit(n) (1LL<<(n))
#define popcount(n) (__builtin_popcountll(n))

using namespace std;

template<class T>bool chmax(T &a, const T &b) { return (a < b) ? (a = b, 1) : 0;}
template<class T>bool chmin(T &a, const T &b) { return (b < a) ? (a = b, 1) : 0;}

using ll = long long;
using R = long double;
const R EPS = 1e-9L; // [-1000,1000]->EPS=1e-8 [-10000,10000]->EPS=1e-7
inline int sgn(const R& r) {return (r > EPS) - (r < -EPS);}
inline R sq(R x) {return sqrt(max(x, 0.0L));}

const int dx[8] = {1, 0, -1, 0, 1, -1, -1, 1};
const int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};

// Problem Specific Parameter:

int n;
ll a[110];

//Appropriately Changed
using W = ll;
using edge = struct {int to, rev; W cap, flow;};
using G = vector<vector<edge>>;

//Appropriately Changed
void add_edge(G &graph, int from, int to, W cap) {
	graph[from].push_back({to, int(graph[to].size()) , cap , 0});
	graph[to].push_back({from, int(graph[from].size()) - 1, 0 , 0});
}

// Description: グラフに対する最大流
// TimeComplexity: $ \mathcal{O}(EV^2) $ but fast
// Verifyed: AOJ GRL_6_A

W dinic(G &graph, int s, int t) {
    const W inf = 1LL << 50;
    const int n = graph.size();
    vector<int> level(n), iter(n);

    auto bfs = [&](int s, int t) {
        fill(begin(level), end(level), -1);
        queue<int> q;
        level[s] = 0, q.push(s);

        while (!q.empty()) {
            int v = q.front(); q.pop();
            for (auto &e : graph[v]) {
                if (level[e.to] == - 1 and e.cap > e.flow) {
                    level[e.to] = level[v] + 1;
                    q.push(e.to);
                }
            }
        }
        return (level[t] !=  -1);
    };

    auto dfs = [&](int v, int t, W f) {
        auto func = [&](int v, int t, W f, auto func)->W{

            if (v == t) return f;
            for (int &i = iter[v]; i < graph[v].size(); i++) {
                edge &e = graph[v][i];

                if (e.cap > e.flow and level[v] < level[e.to]) {

                    W d = func(e.to, t, min(f, e.cap - e.flow), func);

                    if (d > 0) {
                        e.flow += d, graph[e.to][e.rev].flow -= d;
                        return d;
                    }
                }
            }

            return 0;
        };
        return func(v, t, f, func);
    };

    while (bfs(s, t)) {
        fill(begin(iter), end(iter), 0);
        while (dfs(s, t, inf) != 0 );
    }

    W ret = 0;
    for (auto &e : graph[s]) ret += e.flow;
    return ret;
}

const ll inf = 1LL << 50;

int main(void) {
	cin >> n;
	rep(i,n) cin >> a[i];

	const int s = n, t = n + 1, all = t + 1;
	G graph(all);

	rep(i,n){
		if(a[i] < 0){
			add_edge(graph,s,i,-a[i]);
			add_edge(graph,i,t,0);
		}else{
			add_edge(graph,s,i,0);
			add_edge(graph,i,t,a[i]);
		}
	}

	for(int i = 1; i <=n; ++i){
		for(int j = i + 1; j <= n;++j){
			if(j % i) continue;
			add_edge(graph,i-1,j-1,inf);
		}
	}

	ll ans = 0LL;
	rep(i,n) ans += max(0LL,a[i]);
	ans -= dinic(graph,s,t);
	
	cout << ans << endl;
	return 0;
}

Measured memory_bytes: 256