var
        l:array[0..21]of longint;
        a:array[0..21,0..21]of longint;
        n,m,i,j,k,x,y,z,s,ls,r,c:longint;
function min(x,y:longint):longint;
begin
        if x<y then exit(x)
        else exit(y);
end;
procedure dp;
var
        i,j,k:longint;
        f,d:array[0..21,0..21]of longint;
begin
        for i:=0 to n do
        for j:=0 to n do
        f[i,j]:=maxlongint;
        fillchar(d,sizeof(d),0);
        for i:=0 to n do
        for j:=i+1 to n do
        begin
                d[i,j]:=0;
                if i<>0 then
                for k:=1 to c do
                inc(d[i,j],abs(a[j,l[k]]-a[i,l[k]]));
                for k:=1 to c-1 do
                inc(d[i,j],abs(a[j,l[k]]-a[j,l[k+1]]));
        end;
        f[0,0]:=0;
        for i:=1 to n do
        for j:=1 to min(r,i) do
        begin
                for k:=i-1 downto 0 do
                if f[k,j-1]<>maxlongint then
                begin
                        f[i,j]:=min(f[i,j],f[k,j-1]+d[k,i]);
                end;
        end;
        for i:=r to n do
        s:=min(s,f[i,r]);
end;
procedure dg(k:longint);
begin
        if l[0]=c then
        begin
                dp;
                exit;
        end;
        if k>m then exit;
        inc(l[0]);
        l[l[0]]:=k;
        dg(k+1);
        dec(l[0]);
        dg(k+1);
end;
begin
      //  assign(input,'submatrix.in');
     //   reset(input);
     //   assign(output,'submatrix.out');
    //    rewrite(output);
        readln(n,m,r,c);
        for i:=1 to n do
        for j:=1 to m do
        read(a[i,j]);
        s:=maxlongint;
        dg(1);
        writeln(s);
end.
/**************************************************************
	Problem: 2333
	User: admin
	Language: Pascal
	Result: Wrong Answer
****************************************************************/