#include <fstream>
#include <climits>
using namespace std;
ifstream cin("teren.in");
ofstream cout("teren.out");
int n,m,i,j,s[305][305],i1,j1,x,maxi,suma,arie,b;
bool a[305][305];
int main()
{
    cin>>n>>m>>x;maxi=INT_MIN;
    for(i=1;i<=n;i++)
    {
        for(j=1;j<=m;j++)
        {
            cin>>a[i][j];
            s[i][j]=s[i-1][j]+a[i][j];
        }
    }
    for(i1=1;i1<=n;i1++)
    {
        for(j1=i1;j1<=n;j1++)
        {
          suma=0;arie=0;i=1;
           for(j=1;j<=m;j++)
           {
               b=s[j1][j]-s[i1-1][j];
               suma=suma+b;
               while(suma>x)
               {
                   suma=suma-(s[j1][i]-s[i1-1][i]);
                   i++;
               }

               arie=(j1-i1+1)*(j-i+1);
               maxi=max(maxi,arie);
           }
        }
    }
    cout<<maxi;
    return 0;
}