#include<stdio.h>
int ki,ok,s,ii,n,m,x,max,i,j,a[30][30];

int main(){

FILE *f=fopen("teren.in","r");
fscanf(f,"%d %d %d",&n,&m,&x);

 for(i=1;i<=n;i++){
   for(j=1;j<=m;j++){
   fscanf(f,"%d",&a[i][j]);
   }
 }

fclose(f);




  for(i=1;i<n;i++){

  // for(j=1;j<=m;j++){
  // a[0][j]=a[i][j];
  // }

    for(ii=i;ii<=n;ii++){
    ki=0;
    ok=1;

      for(j=1;j<=m;j++){
      a[0][j]+=a[ii][j];
      ki+=a[0][j];

	if(ki>x&&ok){
	s=(ii-i+1)*(j-1);
	   if(s>max)max=s;
	ok=0;
	}

	if(ki<=x&&j==m){
	s=(ii-i+1)*j;
	   if(s>max)max=s;

	}

      }

    }


  }


FILE *g=fopen("teren.out","w");
fprintf(g,"%d",max);
fclose(g);

return 0;
}