#include <fstream>
#include <cmath>
using namespace std;
ifstream fin("teren.in");
ofstream fout("teren.out");
int a[302][302],n,i,j,maxim,x,m,s;
int main()
{
    int i1=0;
    int j1=0;
    fin>>n>>m>>x;
    for(i=1;i<=n;i++)
        for(j=1;j<=m;j++)
            fin>>a[i][j];
    for(i=1;i<=n;i++)
        for(j=1;j<=m;j++)
            a[i][j]=a[i-1][j]+a[i][j-1]-a[i-1][j-1]+a[i][j];
    for(i=1;i<=n;i++)
    {
        for(j=1;j<=m;j++)
        {
            for(i1=i;i1<=n;i1++)
            {
                for(j1=j;j1<=m;j1++)
                {
                    s=a[i1][j1]-a[i-1][j1]-a[i1][j-1]+a[i-1][j-1];
                    if(s<=x)
                    {
                        maxim=max(maxim,(i1-i+1)*(j1-j+1));
                    }
                }
            }
        }
    }
    fout<<maxim;
    return 0;
}