#include <fstream>

using namespace std;

ifstream fin("teren.in");
ofstream fout("teren.out");

int n,m,k,a[303][303];

void Citire()
{
    int i,j,x;
    fin>>n>>m>>k;
    for(i=1;i<=n;i++)
        for(j=1;j<=m;j++)
    {
        fin>>x;
        a[i][j]=a[i-1][j]+a[i][j-1]-a[i-1][j-1]+x;
    }
    fin.close();
}

void Rezolvare()
{
    int i1,i2,s,h,l,j1,j2;
    s=0;
    for(i1=1;i1<=n;i1++)
        for(i2=n;i2>=i1;i2--)
            for(j1=1;j1<=m;j1++)
                for(j2=m;j2>=j1;j2--)
                    if(a[i2][j2]-a[i1-1][j1]-a[i1][j1-1]+a[i1-1][j1-1]==k)
                    {
                        h=i2-i1+1;
                        l=j2-j1+1;
                        s=max(s,h*l);
                    }
    fout<<s<<"\n";
    fout.close();
}

int main()
{
    Citire();
    Rezolvare();
    return 0;
}