#include <cstdio>
#include <algorithm>
using namespace std;

FILE *f=fopen ("teren.in","r");
FILE *g=fopen ("teren.out","w");

bool v[305][305];
int ind[305][305],s[305][305];

int main(){
	int n,m,x,sol=-1;
	
	fscanf (f,"%d%d%d",&n,&m,&x);
	
	for (int i=1;i<=n;++i){
		for (int j=1;j<=m;++j){
			fscanf (f,"%d",&v[i][j]);
			s[i][j]=v[i][j]+s[i-1][j];
		}
	}
	
	for(int i=1;i<=n;++i){
        for(int k=i;k<=n;++k){
            int begin=1,sum=0;
            for(int j=1;j<=m;++j){
                sum+=s[k][j]-s[i-1][j];
                while(sum>x){
                    sum-=s[k][begin]-s[i-1][begin];
                    ++begin;
                }
				sol=max(sol,(j-begin+1)*(k-i+1));
            }
        }
	}

	
	fprintf (g,"%d",sol);
	
	
	return 0;
}