program ex;
type
 data=record
  x,y:integer;
 end;
 ss=array[1..250000]of data;
 sz=array[1..120]of integer;
var
 a,b:ss;
 f:sz;
 f1,f2:text;
 m,n,a1,b1:integer;
procedure init;
 var
  i:integer;
 begin
  assign(f1,'crusade.in');
  assign(f2,'crusade.out');
  reset(f1);
  rewrite(f2);
  readln(f1,n,m,a1,b1);
  for i:=1 to a1 do readln(f1,a[i].x,a[i].y);
  for i:=1 to b1 do readln(f1,b[i].x,b[i].y);
  for i:=1 to m+n do f[i]:=maxint;
  close(f1);
 end;
procedure main;
 var
  i,j:integer;
  t,t1,t2:integer;
 begin
  for i:=1 to a1 do
   begin
    t:=a[i].x+a[i].y;
    t1:=t;
    t2:=t;
    while t1>0 do
     begin
      if t-t1<f[t1] then f[t1]:=t-t1;
      dec(t1);
     end;
    while t2<=m+n do
     begin
      if t2-t<f[t2] then f[t2]:=t2-t;
      inc(t2);
     end;
   end;
  for i:=1 to b1 do
   writeln(f2,f[b[i].x+b[i].y]);
  {for i:=1 to m+n do
   write(f2,f[i],' ');}
 end;
begin
 init;
 main;
 close(f2);
end.