var r:textfile; s:string;
begin
assignfile(r,filename);
reset(r);
al:=0;
while not eof(r) do begin
  inc(al);
  readln(r,s);
end;
closefile(r);

readln(r);

Function GetLinesCountMMF(Const p_strFileName:String):Cardinal;
Const
BUF_SIZE=32*1024*1024;

Type
TFileMapRec=Record
_File:HFILE;
_Map:THandle;
_Size:Int64;
End;

Function OpenFile(Const p_strFileName:String):TFileMapRec;
Var
slo,shi:Cardinal;
Begin
Result._File:=CreateFile(PChar(p_strFileName), GENERIC_READ,FILE_SHARE_READ,Nil,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,0);
slo:=Windows.GetFileSize(Result._File,@shi);
Int64Rec(Result._Size).Lo:=slo;
Int64Rec(Result._Size).Hi:=shi;
Result._Map:=CreateFileMapping(Result._File,Nil,PAGE_READONLY,0,0,Nil);
End;

Procedure CloseFile(Var rp_rFile:TFileMapRec);
Begin
CloseHandle(rp_rFile._Map);
CloseHandle(rp_rFile._File);
End;

Function MapBuff(p_rFile:TFileMapRec;p_nFrom:Int64;p_nCount:Cardinal):Pointer;
Begin
Result:=MapViewOfFile(p_rFile._Map, FILE_MAP_READ,Int64Rec(p_nFrom).Hi,Int64Rec(p_nFrom).Lo,p_nCount);
End;

Procedure UnMapBuff(Var p:Pointer);
Begin
UnmapViewOfFile(p);
End;

Var
_File:TFileMapRec;
Buf:PByteArray;
p:Int64;
LastBufByteIsCR:Boolean;

Function _Count(p_nFrom:Int64;p_nCount:Cardinal):Cardinal;
Var
StartFrom:Integer;
i:Integer;
Begin
Buf:=MapBuff(_File,p_nFrom,p_nCount);
Try
 Result:=0;
 If Not LastBufByteIsCR Then StartFrom:=0 Else
  If Buf[0]<>10 Then StartFrom:=0 Else
   Begin
    Inc(Result);
    StartFrom:=1;
   End;
 For i:=StartFrom to p_nCount-2 Do
  If (Buf[i]=13) and (Buf[i+1]=10) Then Inc(Result);
 LastBufByteIsCR:=Buf[p_nCount-1]=13;
Finally
 UnMapBuff(Pointer(Buf));
End;
End;

Begin
_File:=OpenFile(p_strFileName);
Try
 p:=0;
 Result:=0;
 While True Do
  If (p+BUF_SIZE)>_File._Size Then
   Begin
    Result:=Result+_Count(p,_File._Size-p);
    Break;
   End Else
   Begin
    Result:=Result+_Count(p,BUF_SIZE);
    Inc(p,BUF_SIZE);
   End;
Finally
 CloseFile(_File);
End;
End;

Function GetLinesCountRLN(Const p_strFileName:String):Cardinal;
Var
f:TextFile;
Begin
Result:=0;
AssignFile(f,p_strFileName);Reset(f);
While Not Eof(f) Do
 Begin
  Inc(Result);
  Readln(f);
 End;
CloseFile(f);
End;

Function vtRandomStr(p_nMaxLen:Integer=300):String;
Var
i:Integer;
Begin
SetLength(Result,Random(p_nMaxLen));
For i:=1 to Length(Result) Do
 Result[i]:=Char(Random(223)+32);
End;

procedure TForm1.CreateRndTxtFile;
Var
i:Integer;
f:TextFile;
begin
AssignFile(f,'c:\bigtext.txt'); Rewrite(f);
For i:=0 to 2000000-1 Do WriteLn(f,vtRandomStr(400));
CloseFile(f);
end;

procedure TForm1.Bench;
Var
gtc:Cardinal;
tc:Cardinal;
i:Integer;

Procedure _Tick1;
Begin
 tc:=GetTickCount;
 Memo1.Lines.Add('RLN:'+IntToStr(GetLinesCountRLN('c:\bigtext.txt'))+':'+IntToStr(GetTickCount-tc));
 Application.ProcessMessages;
End;

Procedure _Tick2;
Begin
 tc:=GetTickCount;
 Memo1.Lines.Add('MMF:'+IntToStr(GetLinesCountMMF('c:\bigtext.txt'))+':'+IntToStr(GetTickCount-tc));
 Application.ProcessMessages;
End;

begin
gtc:=GetTickCount;
For i:=0 to 5 Do _Tick1;
Memo1.Lines.Add(IntToStr((GetTickCount-gtc) div 6));
Application.ProcessMessages;
gtc:=GetTickCount;
For i:=0 to 5 Do _Tick2;
Memo1.Lines.Add(IntToStr((GetTickCount-gtc) div 6));
Application.ProcessMessages;
end;

RLN:2000000:6391
RLN:2000000:6359
RLN:2000000:6344
RLN:2000000:6359
RLN:2000000:6344
RLN:2000000:6359
6359
MMF:2000000:1032
MMF:2000000:1046
MMF:2000000:1032
MMF:2000000:1047
MMF:2000000:1031
MMF:2000000:1047
1039
RLN32:2000000:3750
RLN32:2000000:3750
RLN32:2000000:3781
RLN32:2000000:3734
RLN32:2000000:3719
RLN32:2000000:3781
3752

Function GetLinesCountRLNB32(Const p_strFileName:String):Cardinal;
Var
f:TextFile;
Buf:Pointer;
Begin
GetMem(Buf,32*1024*1024);
Result:=0;
AssignFile(f,p_strFileName);SetTextBuf(f,Buf^,32*1024*1024);Reset(f);
While Not Eof(f) Do
 Begin
  Inc(Result);
  Readln(f);
 End;
CloseFile(f);
FreeMem(Buf);
End;