#include <bits/stdc++.h>
#define fi first
#define se second
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define rrep(i,n) for(int i = 1; i <= (n); ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define rng(a) a.begin(),a.end()
#define rrng(a) a.rbegin(),a.rend()
#define maxs(x,y) (x = max(x,y))
#define mins(x,y) (x = min(x,y))
#define limit(x,l,r) max(l,min(x,r))
#define lims(x,l,r) (x = max(l,min(x,r)))
#define isin(x,l,r) ((l) <= (x) && (x) < (r))
#define pb push_back
#define eb emplace_back
#define sz(x) (int)(x).size()
#define pcnt __builtin_popcountll
#define uni(x) x.erase(unique(rng(x)),x.end())
#define snuke srand((unsigned)clock()+(unsigned)time(NULL));
#define show(x) cout<<#x<<" = "<<x<<endl;
#define PQ(T) priority_queue<T,v(T),greater<T> >
#define bn(x) ((1<<x)-1)
#define dup(x,y) (((x)+(y)-1)/(y))
#define newline puts("")
#define v(T) vector<T>
#define vv(T) v(v(T))
using namespace std;
typedef long long int ll;
typedef unsigned uint;
typedef unsigned long long ull;
typedef pair<int,int> P;
typedef tuple<int,int,int> T;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<P> vp;
typedef vector<T> vt;
inline int getInt() { int x; scanf("%d",&x); return x;}
template<typename T>inline istream& operator>>(istream&i,v(T)&v)
{rep(j,sz(v))i>>v[j];return i;}
template<typename T>string join(const v(T)&v)
{stringstream s;rep(i,sz(v))s<<' '<<v[i];return s.str().substr(1);}
template<typename T>inline ostream& operator<<(ostream&o,const v(T)&v)
{if(sz(v))o<<join(v);return o;}
template<typename T1,typename T2>inline istream& operator>>(istream&i,pair<T1,T2>&v)
{return i>>v.fi>>v.se;}
template<typename T1,typename T2>inline ostream& operator<<(ostream&o,const pair<T1,T2>&v)
{return o<<v.fi<<","<<v.se;}
template<typename T>inline ll suma(const v(T)& a) { ll res(0); for (auto&& x : a) res += x; return res;}
const double eps = 1e-10;
const ll LINF = 1001002003004005006ll;
const int INF = 1001001001;
#define dame { puts("-1"); return 0;}
#define yn {puts("Yes");}else{puts("No");}
const int MX = 200005;

// Max flow
// !! Be care of double and INF !!
struct Maxflow {
  typedef ll TT;
  int n;
  vi to, next, head, dist, it;
  vector<TT> lim;
  Maxflow(){}
  Maxflow(int n):n(n),head(n,-1),it(n){}
  void add(int a, int b, TT c=1) {
    next.pb(head[a]); head[a] = sz(to); to.pb(b); lim.pb(c);
    next.pb(head[b]); head[b] = sz(to); to.pb(a); lim.pb(0); 
  }
  void bfs(int sv) {
    dist = vi(n,INF);
    queue<int> q;
    dist[sv] = 0; q.push(sv);
    while (!q.empty()){
      int v = q.front(); q.pop();
      for (int i = head[v]; i != -1; i = next[i]) {
        if (lim[i] && dist[to[i]] == INF) { // double !!
          dist[to[i]] = dist[v]+1; q.push(to[i]);
        }
      }
    }
  }
  TT dfs(int v, int tv, TT nf=LINF) { // INF !!
    if (v == tv) return nf;
    for (; it[v] != -1; it[v] = next[it[v]]) {
      int u = to[it[v]]; TT f;
      if (!lim[it[v]] || dist[v] >= dist[u]) continue; // double !!
      if (f = dfs(u, tv, min(nf, lim[it[v]])), f) { // double !!
        lim[it[v]] -= f;
        lim[it[v]^1] += f;
        return f;
      }
    }
    return 0;
  }
  TT solve(int sv, int tv) {
    TT flow = 0, f;
    while (1) {
      bfs(sv);
      if (dist[tv] == INF) return flow;
      rep(i,n) it[i] = head[i];
      while (f = dfs(sv,tv), f) flow += f;
    }
  }
};
//



int main() {
  int n;
  scanf("%d",&n);
  vi a(n+1);
  rrep(i,n) cin>>a[i];
  int sv = 0, tv = n+1;
  Maxflow g(tv+1);
  rrep(i,n)rrep(j,n) {
    if (i < j && j%i == 0) {
      g.add(j,i,LINF);
    }
  }
  ll ans = 0;
  rrep(i,n) {
    if (a[i] > 0) {
      ans += a[i];
      g.add(sv,i,a[i]);
    } else {
      g.add(i,tv,-a[i]);
    }
  }
  ans -= g.solve(sv,tv);
  cout<<ans<<endl;
  return 0;
}






















Measured memory_bytes: 256