program MayLava;

type
 rec=record
  x,y:longint;
 end;

var
 map:array[1..500,1..500]of longint;
 qe:array[1..250000] of rec;
 p,q:array[1..250000]of rec;
 m,n,a,b,e:longint;

procedure start;
 var
  f:text;
  i,j:longint;
 begin
  assign(f,'crusade.in');
  reset(f);
  readln(f,n,m,a,b);
  for i:=1 to n do
   for j:=1 to m do
    map[i,j]:=maxlongint;
  for i:=1 to a do begin
   readln(f,p[i].x,p[i].y);
   map[p[i].x,p[i].y]:=0;
  end;
  for i:=1 to b do begin
   readln(f,q[i].x,q[i].y);
  end;
  close(f);
 end;

procedure print;
 var
  i:longint;
  f:text;
 begin
  assign(f,'crusade.out');
  rewrite(f);
  for i:=1 to b do
   writeln(f,map[q[i].x,q[i].y]);
  close(f);
  halt;
 end;

procedure hunt(o:longint);
 begin
  with qe[o] do begin
  if (x+1<=n) and (map[x+1,y]>map[x,y]+1) then begin map[x+1,y]:=map[x,y]+1; inc(e); qe[e].x:=x+1; qe[e].y:=y; end;
  if (x-1>=1) and (map[x-1,y]>map[x,y]+1) then begin map[x-1,y]:=map[x,y]+1; inc(e); qe[e].x:=x-1; qe[e].y:=y; end;
  if (y+1<=m) and (map[x,y+1]>map[x,y]+1) then begin map[x,y+1]:=map[x,y]+1; inc(e); qe[e].x:=x; qe[e].y:=y+1; end;
  if (y-1>=1) and (map[x,y-1]>map[x,y]+1) then begin map[x,y-1]:=map[x,y]+1; inc(e); qe[e].x:=x; qe[e].y:=y-1; end;
  end;
  if o+1>e then print
  else hunt(o+1);
 end;

procedure main;
 var
  i:longint;
 begin
  for i:=1 to a do begin
   qe[i].x:=p[i].x;
   qe[i].y:=p[i].y;
  end;
  e:=a;
  hunt(1);
 end;

BEGIN
 start;
 main;
 print;
END.