#include <cstdio>
#include <cstring>
#include <iostream>
using namespace std;
int n,m,xn,yn,K;
int s[1010][1010];
inline int rd()
{
	int ret=0,f=1;	char gc=getchar();
	while(gc<‘0‘||gc>‘9‘)	{if(gc==‘-‘)	f=-f;	gc=getchar();}
	while(gc>=‘0‘&&gc<=‘9‘)	ret=ret*10+gc-‘0‘,gc=getchar();
	return ret*f;
}
inline int calc(int a,int b,int c,int d)
{
	return s[c][d]-s[a][d]-s[c][b]+s[a][b];
}
bool check(int x)
{
	register int i,j,a,b;
	int ret=K;
	for(i=xn;i<=n;i++)	for(j=yn;j<=m;j++)
	{
		for(a=i-xn;a>=0&&calc(a,j-yn,i,j)<x;a--)	for(b=j-yn;b>=0&&calc(a,b,i,j)<x;b--)
		{
			ret--;
			if(!ret)	return 1;
		}
	}
	return 0;
}
int main()
{
	n=rd(),m=rd(),xn=rd(),yn=rd(),K=rd();
	int i,j;
	for(i=1;i<=n;i++)	for(j=1;j<=m;j++)	s[i][j]=s[i-1][j]-s[i-1][j-1]+s[i][j-1]+rd();
	int l=0,r=s[n][m]+1,mid;
	while(l<r)
	{
		mid=(l+r)>>1;
		if(check(mid))	r=mid;
		else	l=mid+1;
	}
	printf("%d",r);
	return 0;
}