#include<bits/stdc++.h>
using namespace std;
int n,m,x,start,total;
bool a[305][305];
int sum[305][305];
int sol;
inline int max(int a,int b)
{
    return a>b?a:b;
}
int main()
{
    freopen("teren.in","r",stdin);
    freopen("teren.out","w",stdout);
    scanf("%d%d%d",&n,&m,&x);
    for(int i=1;i<=n;i++)
    {
        for(int j=1;j<=m;j++)
        scanf("%d",&a[i][j]);
    }
    for(int i=1;i<=n;i++)
    {
        for(int j=1;j<=m;j++) sum[i][j]=sum[i-1][j]+a[i][j];
    }
    for(int l1=1;l1<=n;l1++)
    {
        for(int l2=l1;l2<=n;l2++)
        {
            start=1;
            total=0;
            for(int i=1;i<=m;i++)
            {
                total=total+sum[l2][i]-sum[l1-1][i];
                while(start<=i && total>x)
                {
                    total=total-(sum[l2][start]-sum[l1-1][start]);
                    start++;
                }
            if(total<=x)
            {
                sol=max(sol,(l2-l1+1)*(i-start+1));
            }
            }
        }
    }
    printf("%d\n",sol);
    return 0;
}