#pragma GCC optimize("-O2")
#include<bits/stdc++.h>
using namespace std;
#define sight(c) ('0'<=c&&c<='9')
#define LL long long
#define M 1007
inline void read(int &x){static char c; static int b;for (b=1,c=getchar();!sight(c);c=getchar()) if (c=='-') b=-1;for (x=0;sight(c);c=getchar())x=x*10+c-48; x=x*b;
}
LL sum[M][M];
struct state{int x,y,lx,ly;LL ans;state() {}state(int _x,int _y,int _lx,int _ly):x(_x),y(_y),lx(_lx),ly(_ly){ans=sum[_x-1+lx][_y-1+ly]+sum[_x-1][_y-1]-sum[_x-1+lx][_y-1]-sum[_x-1][_y-1+ly];}inline bool operator <(const state& P)const&{returnP.ans==ans?(P.x==x?(P.y==y?(P.lx==lx?P.ly<ly:P.lx<lx):P.y<y):P.x<x):  P.ans<ans;}
}Now;
#define N 2346007
state hep[N];
int len,n,m,xm,ym,K,ax;
map<state,bool> mp;
void write(LL x){if (x<10) {putchar('0'+x); return;} write(x/10); putchar('0'+x%10);}
inline void writeln(LL x){ if (x<0) putchar('-'),x*=-1; write(x); putchar('\n'); }
inline void writel(LL x){ if (x<0) putchar('-'),x*=-1; write(x); putchar(' '); }
void put(state P){hep[++len]=P,push_heap(hep+1,hep+1+len);}
inline state get() {pop_heap(hep+1,hep+1+len);return hep[len--];}
signed main () {read(n); read(m); read(xm); read(ym); read(K);for (int i=1;i<=n;i++)for (int j=1;j<=m;j++) read(ax),sum[i][j]=sum[i-1][j]+sum[i][j-1]-sum[i-1][j-1]+ax;for (int i=1;i<=n-xm+1;i++)for (int j=1;j<=m-ym+1;j++)  put(state(i,j,xm,ym));
//  for (int i=1;i<=len;i++) hep[i].we();while (K--) {while (Now=get(),1) {if (!mp[Now]) break;}mp[Now]=1;
//      writel(Now.x); writel(Now.y); writel(Now.lx); writel(Now.ly); writeln(Now.ans);if (Now.x+Now.lx<=n) put(state(Now.x,Now.y,Now.lx+1,Now.ly));if (Now.y+Now.ly<=m) put(state(Now.x,Now.y,Now.lx,Now.ly+1));}writeln(Now.ans+1); return 0;
}