program cch(input,output);
const
 xx:array[1..4] of integer=(-1,0,1,0);
 yy:array[1..4] of integer=(0,1,0,-1);
var
 i,j,n,m,s,c,x,y,q,k,x1,y1:integer;
 a:array[1..500,1..500] of integer;
begin
 assign(input,'crusade.in');
 assign(output,'crusade.out');
 reset(input);
 rewrite(output);
 readln(n,m,s,c);
 for i:=1 to n do
  for j:=1 to m do a[i,j]:=maxint;
 for i:=1 to s do
  begin
   readln(x,y);
   a[x,y]:=0;
  end;
 for i:=1 to n*m do
  for j:=1 to n do
   for q:=1 to m do
    if a[j,q]<>maxint then
     for k:=1 to 4 do
      begin
       x1:=j+xx[k]; y1:=q+yy[k];
       if (x1>=1)and(x1<=n)and(y1>=1)and(y1<=m) then
        if a[j,q]+1<a[x1,y1] then a[x1,y1]:=a[j,q]+1;
      end;
 for i:=1 to c do
  begin
   readln(x,y);
   writeln(a[x,y]);
  end;
 close(input);
 close(output);
end.