//#include<algorithm>
#include<stdio.h>
#define DIM 31
//using namespace std;
int n,m,x,a[DIM][DIM],sol[DIM][DIM];
void solve(){
	int i,j,k,l,x0,y0,x1,y1,max;
	scanf("%d%d%d",&n,&m,&x);
	for(i=1; i<=n; ++i)
		for(j=1; j<=m; ++j){
			scanf("%d",&a[i][j]);
			a[i][j]+=a[i][j-1];}
	for(i=1; i<=m; sol[1][i]=a[1][i],++i);
	for(i=2; i<=n; ++i)
		for(j=1; j<=m; ++j)
			sol[i][j]=sol[i-1][j]+a[i][j];
	for(i=max=0; i<n; ++i)
		for(j=0; j<m; ++j)
			for(k=i+1; k<=n; ++k)
				for(l=j+1; l<=m; ++l)
					if(sol[k][l]-(sol[k][j]+sol[i][l]-sol[i][j])<=x&&(k-i)*(l-j)>max){
						max=(k-i)*(l-j);
						x0=i+1;
						y0=j+1;
						x1=k;
						y1=l;}
	printf("%d",max);}
int main(){
	freopen("teren.in","r",stdin);
	freopen("teren.out","w",stdout);
	solve();
	return 0;}