记录编号	8415	评测结果	AAAAAAAAAAW
题目名称	[BYVoid S3] 彩色穿孔卡片	最终得分	90
用户昵称	chengyang	是否通过	未通过
代码语言	Pascal	运行时间	0.812 s
提交时间	2008-11-14 08:01:12	内存使用	0.20 MiB

program punch;
var
  a:array[1..10000,1..2]of longint;
  b:array[1..10000]of boolean;
  n,t:integer;
procedure go;
var
  i,j:longint;
Begin
  assign(input,'punch.in');
  assign(output,'punch.out');
  reset(input);  rewrite(output);
  t:=0;  readln(n);
  for i:=1 to n do begin
    readln(a[i,1],a[i,2]);
    for j:=1 to i-1 do begin
      if b[j] then begin
        if (a[i,1]<=a[j,1])and(a[i,2]>=a[j,2])then begin
          b[j]:=false;
          t:=t-1;
        end;
        if (a[i,1]<a[j,1])and(a[i,2]>a[j,1])and(a[i,2]<a[j,2])then a[j,1]:=a[i,2];
        if (a[i,2]>a[j,2])and(a[i,1]>a[j,1])and(a[i,1]<a[j,2])then a[j,2]:=a[i,1];
     end;
   end;
  b[i]:=true;
  t:=t+1;
  end;
End;
Begin
  go;
  write(t);
  close(input);close(output);
end.