#include<cstdio>

#include<algorithm>

using namespace std;

const int maxn=;

typedef long long LL;

struct node{

    int l,r;

    LL sum,lsum,rsum;  //sum为区间和，lsum最小前缀，rsum最小后缀

}tr[maxn<<];

//L[i]~R[i]为满足a[i]为最小的最大区间

int n,p,a[maxn],L[maxn],R[maxn],stk[maxn];

LL ans;

node gets(node a,node b){

    node t;

    t.l=a.l,t.r=b.r;

    t.sum=a.sum+b.sum;

    t.lsum=min(a.lsum,a.sum+b.lsum);

    t.rsum=min(b.rsum,b.sum+a.rsum);

    return t;

}

void build(int v,int l,int r){

    tr[v].l=l,tr[v].r=r;

    if(l==r){

        tr[v].sum=a[r];

        tr[v].lsum=min(a[r]*1LL,0LL);

        tr[v].rsum=min(a[r]*1LL,0LL);

        return;

    }

    int mid=(l+r)>>;

    build(v<<,l,mid);

    build(v<<|,mid+,r);

    tr[v]=gets(tr[v<<],tr[v<<|]);

}

void query(node &x,int v,int l,int r){

    if(l<=tr[v].l&&r>=tr[v].r){

        x=gets(x,tr[v]);

        return;

    }

    int mid=(tr[v].l+tr[v].r)>>;

    if(l<=mid) query(x,v<<,l,r);

    if(r>mid) query(x,v<<|,l,r);

}

int main(){

    scanf("%d",&n);

    for(int i=;i<=n;++i)

        scanf("%d",&a[i]);

    a[]=a[n+]=0xcfcfcfcf;

    stk[p=]=;   //利用单调栈求L[i],R[i]

    for(int i=;i<=n;++i){

        while(a[stk[p]]>=a[i]) --p;

        L[i]=stk[p]+;

        stk[++p]=i;

    }

    stk[p=]=n+;

    for(int i=n;i>=;--i){

        while(a[stk[p]]>=a[i]) --p;

        R[i]=stk[p]-;

        stk[++p]=i;

    }

    build(,,n);

    for(int i=;i<=n;++i){

        if(a[i]>){

            node t;

            t.sum=t.lsum=t.rsum=;

            query(t,,L[i],R[i]);

            if(a[i]*t.sum>ans) ans=a[i]*t.sum;

        }

        else if(a[i]<){

            LL tmp=;

            node t;

            t.sum=t.lsum=t.rsum=;

            query(t,,L[i],i);

            tmp+=t.rsum;

            t.sum=t.lsum=t.rsum=;

            query(t,,i,R[i]);

            tmp+=t.lsum;

            tmp-=a[i];

            if(tmp*a[i]>ans) ans=tmp*a[i];

        }

    }

    printf("%lld\n",ans);

    return ;

}