C++ :

#include       <map>  
#include       <set>  
#include     <stack>
#include     <cmath>  
#include     <ctime>  
#include     <queue>  
#include    <cstdio>  
#include    <vector>  
#include    <string>  
#include    <bitset>  
#include   <cstring>  
#include   <cstdlib>  
#include  <iostream>  
#include <algorithm>  
using namespace std;  

#ifndef unix  
    #define lld "%I64d"  
    #define llu "%I64u"  
#else  
    #define lld "%lld"  
    #define llu "%llu"  
#endif  

#define FOR(a,b,c)  for(int (a)=b;(a)<=(c);++(a))  
#define FORD(a,b,c) for(int (a)=b;(a)>=(c);--(a))  
#define FORV(a,t,b) for(vector<t>::iterator a=b.begin();a!=b.end();++a)  
#define MAX(a,b)                   a=max(a,b)  
#define MIN(a,b)                   a=min(a,b)  
#define BLA                      printf("\n")  
#define pb                          push_back  
#define mp                          make_pair  
#define gc                            getchar  
#define RT                             return  
#define BB                             second  
#define AA                              first  
#define bk                              break  
#define LINF             0x3f3f3f3f3f3f3f3fll  
#define INF                        0x3f3f3f3f  
#define eps                              1e-8  
#define DINF                             1e20  

//#define Generator  

typedef long long           ll;  
typedef unsigned            ui;  
typedef unsigned long long ull;  
typedef pair<int,int>      pii;  
typedef pair<ll ,ll >      pll;  

const int MAXN= 0;  
const int MOD = 0;  

template <class T> inline void CLR(T &g)             {T t;swap(t,g);}  
template <class T> inline void CLR(T &g,int a){memset(g,a,sizeof g);}  
template <class T> inline void CPY(T &a,T &b) {memcpy(a,b,sizeof a);}  
template <class T> inline bool inr(T a,T b,T c)  {RT (a>=b && a<=c);}  
inline int acc(int a,int b)                    {RT !!(a & (1<<b-1));}  
inline int fil(int a,int b,int c)    {RT a & ~(1<<b-1) | (1<<b-1)*c;}  
  
int N, M, K, Q, R, C; 

int a[20][20];
int f[20][20];//f[i][j]表示 已经选择i列 上一列是j
int sum[20], d[20], csum[20][20];

int main(){  
	#ifndef Generator  
	#ifndef ONLINE_JUDGE  
		freopen("submatrix.in" ,"r",stdin );  
		freopen("submatrix.out","w",stdout);  
	#endif  
	#endif  
	#ifdef Generator  
		freopen("input.txt","w",stdout);  
		srand((ui)time(NULL));  
	#endif  
	int T, o=0;
	scanf("%d%d%d%d", &N, &M, &R, &C);
	FOR(i, 1, N)
		FOR(j, 1, M)
			scanf("%d", &a[i][j]);
	int ans=INF;
	FOR(i, 1, (1<<N)-1){//枚举哪些行被选入矩阵
		int cnt=0;
		FOR(j, 1, N)
			if (acc(i, j)) d[++cnt]=j;
		if (cnt != R) continue;
		FOR(j, 1, M){
			sum[j]=0;
			FOR(k, 1, R-1)
				sum[j] += abs(a[d[k]][j]-a[d[k+1]][j]);
		}
		FOR(j, 1, M)
			FOR(k, j+1, M){
				csum[j][k]=0;
				FOR(l, 1, R)
					csum[j][k] += abs(a[d[l]][j]-a[d[l]][k]);
			}
		CLR(f, 0x3f);
		f[0][0]=0;
		FOR(j, 1, C){
			FOR(k, 1, M){
				int tot=0;
				FOR(l, 0, k-1)
					MIN(f[j][k], f[j-1][l]+csum[l][k]+sum[k]);
			}
		}
		FOR(j, 1, M)
			MIN(ans, f[C][j]);
	}
	printf("%d\n", ans);
	RT 0;
}