NUSS1017

#include<stdio.h>
#include<string.h>

int n, i, j, k, mxa;
bool f[2001][2001];
int r[2001][2001];

int uu[2001][2001];

int main()
{
    while(scanf("%d",&n)==1)
    {
        mxa=0;
        for(i=0;i<n;i++)
            for(j=0;j<n;j++)
                scanf("%d",&f[i][j]);
        /**////
        for(i=0;i<n;i++)
        {
            int c=0;
            for(j=n-1;j>=0;j--)
            {
                if(f[i][j]==0)c++;
                else
                    c=0;
                r[i][j]=c;
            }
        }
        memset(uu,0,sizeof(uu));
        for(i=0;i<n;i++)
        {
            for(j=0;j<n;j++)
            {
                if(i!=0 && r[i][j]<=r[i-1][j])
                {
                    if(r[i][j]==r[i-1][j])
                        uu[i][j]=uu[i-1][j]+1;
                    else
                    {
                        uu[i][j]=2;
                    int ii=2;
                    while(i-ii >=0 && r[i][j]<=r[i-ii][j])
                    {
                        if(r[i][j]==r[i-ii][j])
                        {
                            uu[i][j]=ii+uu[i-ii][j];
                            break;
                        }
                        uu[i][j]++;
                        ii++;
                    }
                    }
                }
                else
                    uu[i][j]=1;
            }
        }
        for(i=0;i<n;i++)
        {
            for(j=0;j<n;j++)
            {
                if(mxa<r[i][j]*uu[i][j])
                    mxa=r[i][j]*uu[i][j];
            }
        }//
        for(j=0;j<n;j++)
        {
            int c=0;
            for(i=n-1;i>=0;i--)
            {
                if(f[i][j]==0)c++;
                else
                    c=0;
                r[i][j]=c;
            }
        }
        memset(uu,0,sizeof(uu));
        for(j=n-1;j>=0;j--)
        {
            for(i=0;i<n;i++)
            {
                if(j!=n-1 && r[i][j]<=r[i][j+1])
                {
                    if(r[i][j]==r[i][j+1])
                        uu[i][j]=uu[i][j+1]+1;
                    else
                    {
                        uu[i][j]=2;
                    int ii=2;
                    while(j+ii <n && r[i][j]<=r[i][j+ii])
                    {
                        if(r[i][j]==r[i][j+ii])
                        {
                            uu[i][j]=ii+uu[i][j+ii];
                            break;
                        }
                        uu[i][j]++;
                        ii++;
                    }
                    }
                }
                else
                    uu[i][j]=1;
            }
        }
        for(i=0;i<n;i++)
        {
            for(j=0;j<n;j++)
            {
                if(mxa<r[i][j]*uu[i][j])
                    mxa=r[i][j]*uu[i][j];
            }
        }//
        for(i=0;i<n;i++)
        {
            int c=0;
            for(j=0;j<n;j++)
            {
                if(f[i][j]==0)c++;
                else
                    c=0;
                r[i][j]=c;
            }
        }
        memset(uu,0,sizeof(uu));
        for(j=0;j<n;j++)
        {
            for(i=n-1;i>=0;i--)
            {
                if(i!=n-1 && r[i][j]<=r[i+1][j])
                {
                    if(r[i][j]==r[i+1][j])
                        uu[i][j]=uu[i+1][j]+1;
                    else
                    {
                        uu[i][j]=2;
                    int ii=2;
                    while(i+ii <n && r[i][j]<=r[i+ii][j])
                    {
                        if(r[i][j]==r[i+ii][j])
                        {
                            uu[i][j]=ii+uu[i+ii][j];
                            break;
                        }
                        uu[i][j]++;
                        ii++;
                    }
                    }
                }
                else
                    uu[i][j]=1;
            }
        }
        for(i=0;i<n;i++)
        {
            for(j=0;j<n;j++)
            {
                if(mxa<r[i][j]*uu[i][j])
                    mxa=r[i][j]*uu[i][j];
            }
        }//
        for(j=0;j<n;j++)
        {
            int c=0;
            for(i=0;i<n;i++)
            {
                if(f[i][j]==0)c++;
                else
                    c=0;
                r[i][j]=c;
            }
        }
        memset(uu,0,sizeof(uu));
        for(i=0;i<n;i++)
        {
            for(j=0;j<n;j++)
            {
                if(j!=0 && r[i][j]<=r[i][j-1])
                {
                    if(r[i][j]==r[i][j-1])
                        uu[i][j]=uu[i][j-1]+1;
                    else
                    {
                        uu[i][j]=2;
                    int ii=2;
                    while(i-ii >=0 && r[i][j]<=r[i][j-ii])
                    {
                        if(r[i][j]==r[i][j-ii])
                        {
                            uu[i][j]=ii+uu[i][j-ii];
                            break;
                        }
                        uu[i][j]++;
                        ii++;
                    }
                    }
                }
                else
                    uu[i][j]=1;
            }
        }
        for(i=0;i<n;i++)
        {
            for(j=0;j<n;j++)
            {
                if(mxa<r[i][j]*uu[i][j])
                    mxa=r[i][j]*uu[i][j];
            }
        }

        printf("%d\n",mxa);
    }
    return 0;
}