type
 aa=record
  x,y,d:longint;
 end;

var
 m,n,k,i,j,t,ans,tot,x,y,d:longint;
 a:array[0..2000] of aa;

procedure qs(l,r:longint);
var
 i,j,mid:longint;
 t:aa;
begin
 i:=l;
 j:=r;
 mid:=a[(l+r) div 2].d;
 while i<=j do
 begin
  while a[i].d>mid do inc(i);
  while a[j].d<mid do dec(j);
  if i<=j then
  begin
    t:=a[i];
    a[i]:=a[j];
    a[j]:=t;
    inc(i);
    dec(j);
  end;
 end;
 if l<j then qs(l,j);
 if i<r then qs(i,r);
end;

begin
 readln(m,n,k);
 for i:=1 to m do
 begin
  for j:=1 to n do
  begin
   read(d);
   if d<>0 then
   begin
    inc(tot);
    a[tot].d:=d;
    a[tot].x:=i;
    a[tot].y:=j;
   end;
  end;
  readln;
 end;

 qs(1,tot);
 k:=k-2;

 t:=0;
 x:=1;
 y:=a[1].y;
 for i:=1 to tot do
 begin
  t:=t+1+abs(a[i].x-x)+abs(a[i].y-y)+a[i].x-1;
  if t<=k then
  begin
   inc(ans,a[i].d);
   x:=a[i].x;
   y:=a[i].y;
  end;
  t:=t-(a[i].x-1);
 end;

 writeln(ans);
end.

/**************************************************************
	Problem: 2245
	User: admin
	Language: Pascal
	Result: Wrong Answer
****************************************************************/