#include <fstream>
#include <bitset>
#include <iostream>
using namespace std;
ifstream fin ("teren.in");
ofstream fout("teren.out");
int b[301][301];
bitset <301> a[301];
int n,m,t,ma;

void cit()	
{ int i,j;
fin>>n>>m>>t;
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++)
       b[i][j]=b[i-1][j]+b[i][j-1]-b[i-1][j-1]+a[i][j];

}

void cal()
{ int i,i1,j1,i2,j2;
for(i1=1; i1<=n; i1++)
    for(j1=1; j1<=m; j1++)
        for(i2=n; i2>=i1; i2--)
            for(j2=m; j2>=j1; j2--) 
    {  
		if(b[i2][j2]-b[i2][j1-1]-b[i1-1][j2]+b[i1-1][j1-1]<=t && ma<(i2-i1+1)*(j2-j1+1))
			{ma=(i2-i1+1)*(j2-j1+1);

			}
    }


}

int main()
{ cit();
cal();
fout<<ma;
return 0;
}