1 #include <bits/stdc++.h>
2 #define _for(i,a,b) for(int i = (a);i < b;i ++)
3
4 typedef long long ll;
5 using namespace std;
6 inline ll read()
7 {
8 ll ans = 0;
9 char ch = getchar(), last = ' ';
10 while(!isdigit(ch)) last = ch, ch = getchar();
11 while(isdigit(ch)) ans = (ans << 1) + (ans << 3) + ch - '0', ch = getchar();
12 if(last == '-') ans = -ans;
13 return ans;
14 }
15 inline void write(ll x)
16 {
17 if(x < 0) x = -x, putchar('-');
18 if(x >= 10) write(x / 10);
19 putchar(x % 10 + '0');
20 }
21 int n,m,r,c;
22 int num[18][18];
23 int dp[18][18];
24 int lc[18],hc[18][18];
25 int df[20] = {0},dfend = 1;
26 int rnt = 0x3f3f3f3f;
27 void pre()
28 {
29 memset(lc,0,sizeof(lc));
30 memset(hc,0,sizeof(hc));
31 _for(i,1,r)
32 _for(j,1,m+1)
33 lc[j] += abs(num[df[i]][j]-num[df[i+1]][j]);
34 _for(i,1,m+1)
35 _for(j,i+1,m+1)
36 _for(k,1,r+1)
37 hc[i][j] += abs(num[df[k]][i]-num[df[k]][j]);
38 }
39
40 void pick()
41 {
42 _for(i,1,m+1)
43 {
44 _for(j,1,min(c+1,i+1))
45 {
46 if(1==j)
47 dp[i][j] = lc[i];
48 else
49 {
50 dp[i][j] = 0x3f3f3f3f;
51 for(int k = j-1; k < i; k ++)
52 dp[i][j] = min(dp[i][j],dp[k][j-1]+lc[i]+hc[k][i]);
53 }
54 }
55 if(i>=c)
56 rnt = min(rnt,dp[i][c]);
57 }
58 }
59 void dfs(int ii)
60 {
61 if(ii>n)
62 {
63 pre();
64 pick();
65 return ;
66 }
67 if(r-dfend==n-ii)
68 {
69 df[dfend++] = ii;
70 dfs(ii+1);
71 dfend --;
72 return ;
73 }
74 dfs(ii+1);
75 if(dfend<=r)
76 {
77 df[dfend++] = ii;
78 dfs(ii+1);
79 dfend --;
80 }
81 }
82
83 void solve()
84 {
85 dfs(1);
86 }
87
88 int main()
89 {
90 n = read(), m = read(),r = read(),c = read();
91
92 _for(i,1,n+1)
93 _for(j,1,m+1)
94 num[i][j] = read();
95 solve();
96 write(rnt);
97 return 0;
98 }
