#include <iostream>
#include <fstream>
#include <cmath>  
#include <cstdlib>
#include <ctime>
#include <algorithm>
#include <numeric>
#include <functional>
#include <string> 
#include <vector>
#include <bitset>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <deque>
#include <random>


using namespace std;
using ll = long long;
using ull = unsigned long long;

#define REP(i,n) for(long long i = 0; i < (n); i++)
#define FOR(i, m, n) for(long long i = (m);i < (n); ++i)
#define ALL(obj) (obj).begin(),(obj).end()

template<class T> using V = vector<T>;
template<class T, class U> using P = pair<T, U>;

const ll MOD = (ll)1e9 + 7;
const ll MOD2 = 998244353;
const ll LLINF = (ll)1e18;
const ll INTINF = (ll)1e9;
const long double PI = 3.1415926535897932384626433;

template <class T> void corner(bool flg, T hoge) { if (flg) { cout << hoge << endl; exit(0); } }
template <class T, class U>ostream &operator<<(ostream &o, const map<T, U>&obj) { o << "{"; for (auto &x : obj) o << " {" << x.first << " : " << x.second << "}" << ","; o << " }"; return o; }
template <class T>ostream &operator<<(ostream &o, const set<T>&obj) { o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr) o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o; }
template <class T>ostream &operator<<(ostream &o, const vector<T>&obj) { o << "{"; for (int i = 0; i < (int)obj.size(); ++i)o << (i > 0 ? ", " : "") << obj[i]; o << "}"; return o; }
template <class T, class U>ostream &operator<<(ostream &o, const pair<T, U>&obj) { o << "{" << obj.first << ", " << obj.second << "}"; return o; }
template <template <class tmp>  class T, class U> ostream &operator<<(ostream &o, const T<U> &obj) { o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr)o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o; }
void print(void) { cout << endl; }
template <class Head> void print(Head&& head) { cout << head; print(); }
template <class Head, class... Tail> void print(Head&& head, Tail&&... tail) { cout << head << " "; print(forward<Tail>(tail)...); }
template <class T> void chmax(T& a, const T b) { a = max<T>(a, b); }
template <class T> void chmin(T& a, const T b) { a = min<T>(a, b); }
void YN(bool flg) { cout << ((flg) ? "YES" : "NO") << endl; }
void Yn(bool flg) { cout << ((flg) ? "Yes" : "No") << endl; }
void yn(bool flg) { cout << ((flg) ? "yes" : "no") << endl; }

// O()
template <class T> class Dinic {
public:
	struct info {
		int to, rev;
		T cap;
	};
	T ini, inf;
	vector<vector<info>> edge;
	vector<int> level, iter;

	Dinic(int N, T ini, T inf) : edge(N), level(N), iter(N), ini(ini), inf(inf) {
		// do nothing
	}

	void make_edge(int from, int to, T cap) {
		edge[from].push_back({ to, (int)edge[to].size(), cap });
		edge[to].push_back({ from, (int)edge[from].size() - 1, ini });
	}

	void bfs(int start) {
		for (int i = 0; i < level.size(); ++i) level[i] = -1;
		queue<int> q;
		level[start] = 0;
		q.push(start);
		while (q.size()) {
			int from = q.front();
			q.pop();
			for (auto& e : edge[from]) {
				if (e.cap > 0 && level[e.to] < 0) {
					level[e.to] = level[from] + 1;
					q.push(e.to);
				}
			}
		}
	}

	T dfs(int from, int goal, T flow) {
		if (from == goal) return flow;
		for (int& i = iter[from]; i < edge[from].size(); ++i) {
			auto& e = edge[from][i];
			if (e.cap <= 0 || level[from] >= level[e.to]) continue;
			T dflow = dfs(e.to, goal, min(flow, e.cap));
			if (dflow <= 0) continue;
			e.cap -= dflow;
			edge[e.to][e.rev].cap += dflow;
			return dflow;
		}
		return ini;
	}

	T maxflow(int start, int goal) {
		T maxflow = ini;
		while (1) {
			bfs(start);
			if (level[goal] < 0) return maxflow;
			for (int i = 0; i < iter.size(); ++i) iter[i] = 0;
			T flow;
			while ((flow = dfs(start, goal, inf))>0) maxflow += flow;
		}
	}
};

template <class T> class Ford_Fulkerson {
public:
	struct info {
		int to, rev;
		T cap;
	};
	T ini, inf;
	vector<vector<info>> edge;
	vector<bool> visit;

	Ford_Fulkerson(int N, T ini, T inf) : edge(N), visit(N), ini(ini), inf(inf) {
		// do nothing
	}

	void make_edge(int from, int to, T cap) {
		edge[from].push_back({ to, (int)edge[to].size(), cap });
		edge[to].push_back({ from, (int)edge[from].size() - 1, ini });
	}

	T dfs(int from, int goal, T flow) {
		if (from == goal) return flow;
		visit[from] = false;
		for (int i = 0; i < edge[from].size(); ++i) {
			if (visit[edge[from][i].to] && edge[from][i].cap > ini) {
				T dflow = dfs(edge[from][i].to, goal, min(flow, edge[from][i].cap));
				if (dflow > 0) {
					edge[from][i].cap -= dflow;
					edge[edge[from][i].to][edge[from][i].rev].cap += dflow;
					return dflow;
				}
			}
		}
		return ini;
	}

	T maxflow(int start, int goal) {
		T maxflow = ini;
		while (1) {
			for (int i = 0; i < edge.size(); ++i) visit[i] = true;
			T flow = dfs(start, goal, inf);
			if (flow == ini) return maxflow;
			maxflow += flow;
		}
	}
};

int main() {
	int N; cin >> N;
	V<ll> a(N+1,0);
	for (int i = 1; i <= N; ++i) cin >> a[i];
	Ford_Fulkerson<ll> d(N+2, 0, 1e15);
	for (int i = 1; i <= N; ++i){
		if(a[i] <= 0) d.make_edge(0, i, -a[i]);
		else d.make_edge(i, N+1, a[i]);
	}
	for (int i = 1; i <= N; ++i) {
		for(int j = 2*i; j <= N; j += i){
			d.make_edge(i, j, (ll)1e15);
		}
	}
	ll sum = 0;
	for (int i = 1; i <= N; ++i) sum += max(a[i], 0LL);
	cout << sum - d.maxflow(0, N+1) << endl;
	return 0;
}



Measured memory_bytes: 256