program e1;
 const
  d:array[1..4,1..2] of integer=((0,1),(0,-1),(1,0),(-1,0));
  maxn=500; maxm=500;
 var
    n,m,a,b:integer;
    g:array[1..maxn,1..maxm] of integer;
    ax,bx,ay,by:array[1..maxn*maxm] of integer;

procedure init;
 var
     i:integer;
 begin
   readln(n,m,a,b);
   for i:=1 to a do read(ax[i],ay[i]);
   for i:=1 to b do read(bx[i],by[i]);
 end;

procedure fill(x,y:integer);
 var
     i,xx,yy:integer;

 begin
  for i:=1 to 4 do
    begin
    xx:=x+d[i,1]; yy:=y+d[i,2];
    if (xx>=1) and (xx<=n) and (yy>=1) and (yy<=m)
    then if (g[x,y]+1<g[xx,yy]) or (g[xx,yy]=-1)
            then begin
                 g[xx,yy]:=g[x,y]+1;
                 fill(xx,yy);
                 end;
    end;
 end;


procedure main;
 var
    i:integer;
 begin
  fillchar(g,sizeof(g),$FF);
  for i:=1 to a do
    begin
    g[ax[i],ay[i]]:=0;
    fill(ax[i],ay[i]);
    end;
  for i:=1 to b do
  writeln(g[bx[i],by[i]]);

 end;



begin
 assign(input,'crusade.in');
 assign(output,'crusade.out');
 reset(input); rewrite(output);
 init;
 main;
 close(input); close(output);
end.