记录编号	7500	评测结果	AAAAAAAAAA
题目名称	[BYVoid S1] 血色叛徒	最终得分	100
用户昵称	王瑞祥K	是否通过	通过
代码语言	Pascal	运行时间	0.528 s
提交时间	2008-11-10 16:29:14	内存使用	2.97 MiB

program crusade(input,output);
type
 point=record
  x,y:integer;
end;
const
 k:array[1..4]of point=((x:1;y:0),(x:0;y:1),(x:-1;y:0),(x:0;y:-1));
var
 sou,goal:array[1..250000]of point;
 ans:array[1..500,1..500]of longint;
 m,n,a,b,dep:longint;
procedure ini;
var i,j:longint;
begin
 assign(input,'crusade.in');assign(output,'crusade.out');
 reset(input);rewrite(output);
 readln(n,m,a,b);
 for i:=1 to n do
  for j:=1 to m do
   ans[i,j]:=-1;
 for i:=1 to a do begin readln(sou[i].x,sou[i].y);ans[sou[i].x,sou[i].y]:=0;end;
 for i:=1 to b do readln(goal[i].x,goal[i].y);
 dep:=0;
end;
procedure bfs(x,y:longint);
var i,j,xx,yy:longint;
begin
 inc(dep);
 for i:=x to y do
  for j:=1 to 4 do begin
   xx:=sou[i].x+k[j].x; yy:=sou[i].y+k[j].y;
   if (xx>0)and(xx<=n)and(yy>0)and(yy<=m)and(ans[xx,yy]=-1)then begin
    ans[xx,yy]:=dep;
    inc(a);
    sou[a].x:=xx; sou[a].y:=yy;
   end;
  end;
 if a>=y+1 then bfs(y+1,a);
end;
procedure print;
var i:longint;
begin
 for i:=1 to b do
 writeln(ans[goal[i].x,goal[i].y]);
 close(input);close(output);
end;
begin
 ini;
 bfs(1,a);
 print;
end.