#include <stdio.h>
int a[301][301],b[301][301];
int main()
{
	FILE *in,*out;
	int n,m,x,max,i,j,i2,j2;
	in=fopen("teren.in","r");
	out=fopen("teren.out","w");
	fscanf(in,"%d%d%d",&n,&m,&x);
	for (i=0;i<=n;i++)
		a[i][0]=0;
	for (j=0;j<=m;j++)
		a[0][j]=0;
	for (i=1;i<=n;i++)
		for (j=1;j<=m;j++)
			fscanf(in,"%d",&a[i][j]);
	max=0;
	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];
			if (a[i][j])
				b[i][j]++;
			if (b[i][j]<=x&&i*j>max)
				max=i*j;
		}
	for (i=1;i<=n;i++)
		for (j=1;j<=m;j++)
			for (i2=i;i2<=n;i2++)
				for (j2=j;j2<=m;j2++)
				{
					if (b[i2][j2]+b[i][j]-b[i2][j-1]+b[i-1][j2]<=x&&(i2-i+1)*(j2-j+1)>max)
						max=(i2-i+1)*(j2-j+1);
						
				}
	fprintf(out,"%d\n",max);
	fclose(in);
	fclose(out);
	return 0;
}