#include<cstdio>

#include<iostream>

#include<algorithm>

#include<cstring>

#define R register int

using namespace std;

inline int g() {

    R ret=; register char ch; while(!isdigit(ch=getchar())) ;

    do ret=ret*+(ch^); while(isdigit(ch=getchar())); return ret;

}

int n,len,sum,cnt;

int a[];

bool v[],flg;

inline int _upper_bound(int l,int r,const int& dst) 
　　{while(l<r) {R md=l+r>>; if(a[md]<=dst) r=md; else l=md+;} return l;}

void dfs(int stk,int res,int lst) {

    if(!res) { if(stk==cnt) {flg=true; return ;} R i;

        for(i=;i<=n;++i) if(!v[i]) break;

        v[i]=true; dfs(stk+,len-a[i],i); v[i]=false; if(flg) return ;

    } R tmp=_upper_bound(lst+,n,res),f=;

    for(R i=tmp;i<=n;++i) if(!v[i]&&f!=a[i]) {

        v[i]=true; dfs(stk,res-a[i],i); v[i]=false; f=a[i];

        if(flg) return; if(res==a[i]||res==len) return ;

    }

}

signed main() {

    R N=g();

    for(R i=,x;i<=N;++i) {

        x=g(); if(x>) continue;

        a[++n]=x,sum+=x;

    } sort(a+,a+n+,greater<int>());

    for(len=a[];len<=sum>>;++len) {

        if(sum%len) continue; cnt=sum/len;

        memset(v,false,sizeof(v)); v[]=true;

        dfs(,len-a[],); if(flg) break;

    } printf("%d\n",flg?len:sum);

}