#include<cstdio>
#include<vector>
#include<list>
#define ST first
#define ND second
#define MP make_pair
#define PB push_back
#define FOREACH(it,c) for(auto it=(c).begin();it!=(c).end();++it)
using namespace std;
typedef long long LL;
typedef pair<int,int> PII;
typedef vector<LL> VLL;
typedef vector<int> VI;
typedef vector<char> VC;

int main()
{
    int n,i,j;
    LL b,s,k;
    scanf("%d",&n);
//    VI t(n);
    VLL kw;
    VLL sm;
    LL st=0;
    s=k=0;
    kw.PB(0);
    sm.PB(0);
    for(i=0;i<n;++i)
    {
        scanf("%lld",&b);
        if(b*st<0)
        {
            kw.PB(k);
            sm.PB(s);
        }
        k+=b*b;
        s+=b;
        st=b;
    }
    kw.PB(k);
    sm.PB(s);
//    FOREACH(it,kw)
//        printf("%lld ",*it);
//    printf("\n");
//    FOREACH(it,sm)
//        printf("%lld ",*it);
    LL m=0;
    for(i=0;i<(int)kw.size();++i)
        for(j=i;j<(int)kw.size();++j)
        {
            m=max(m,kw[i]-kw[j]+(sm[j]-sm[i])*(sm[j]-sm[i]));
        }
    printf("%lld",m/2);
}