/** @JUDGE_ID: GOKURI_SQUEEZE ??? C++ */
#include <iostream>
#include <vector>
#include <string>
#include <map>
#include <set>
#include <algorithm>
#include <fstream>
#include <queue>
#include <climits>
using namespace std;

#define FNAME "coins.txt"
#define cin fin

typedef int vert;
typedef int len_t;
typedef pair<len_t, vert> edge;
typedef vector<edge>      edges;
typedef vector<vector<vert> > graph;

len_t dijkstra( graph& G, vert src, size_t limit )
{
  vector<len_t> shtstlen(G.size(), -1);

  int mp=0;
  vector<int> frontier;
  
  frontier.push_back(src);
  shtstlen[src] = 0;
  while( !frontier.empty() )
    {
      vector<int> new_f;
      for(int i = 0; i < frontier.size(); i++) {
        const vector<vert>& ne = G[frontier[i]];
        for(int j = 0; j < ne.size(); j++) {
          if(shtstlen[ne[j]] < 0) {
            shtstlen[ne[j]] = mp + 1;
            new_f.push_back(ne[j]);
          }
        }
      }
      frontier = new_f;
      mp++;
    }
  
  int result = INT_MIN;
  for(int i = 0; i < limit; i++)
    result = max(result, shtstlen[i]);
  return result;
}

int main()
{
  ifstream fin(FNAME);
  if(!fin) return -1;
  
  int n;
  while(cin >> n) {
    vector<int> coins;
    coins.push_back(1);
    for(int i = 1; i <= n; i++) {
      int a; cin >> a;
      coins.push_back(a);
    }
    //sort(coins.begin(), coins.end());
    
    graph g(2 * coins.back());
    for(int i = 0; i < g.size(); i++)
      for(int j = 0; j < coins.size(); j++) {
        if(i + coins[j] >= g.size()) continue;
        g[i + coins[j]].push_back(i);
        g[i].push_back(i + coins[j]);
      }
    
    cout << dijkstra(g, 0, coins.back()) << endl;
  }
  
  return 0;
}