#include <fstream>

using namespace std;
ifstream cin("teren.in");
ofstream cout("teren.out");
int ar,armx,X,m,n,s[310][310],j1,j2,x;
int main()
{
    cin>>n>>m>>X;
    for(int i=1;i<=n;i++)
        for(int j=1;j<=m;j++)
            cin>>x,s[i][j]=s[i-1][j]+s[i][j-1]-s[i-1][j-1]+x;

    for(int i1=1;i1<=n;i1++)
        for(int i2=i1;i2<=n;i2++)
        {
            j1=1;j2=1;
            while(j1<=m)
            {
                while(j2<=m&&(s[i2][j2]-s[i1-1][j2]-s[i2][j1-1]+s[i1-1][j1-1])<=X)
                    j2++;
                j2--;

                ar=(j2-j1+1)*(i2-i1+1);
                armx=max(ar,armx);

                j1++;
            }
        }

    cout<<armx<<'\n';

    return 0;
}