program big_mess { big_mess # < in > out } ;
{ Reads an exported mail/news file and reports long messages.  Parameter
  '#' is number of lines, including header, over which is long.  Count is
  approximate as the position of Message-ID in the headers will vary.
  Lines in the body starting Message-ID: will deceive program. }
var S1, S2 : string ;
N1, N2, NM : longint ;
J : integer ;
const Over : longint = 100 ; MID = 'Message-ID:' ; Sp = #32 ;

procedure MayWrite ;
begin
  if (N1-N2)>Over then
    Writeln(NM:5, Sp, N2:9, Sp, N1-N2:8, Sp, Copy(S2, Length(MID)+2, 255)) ;
end {MayWrite} ;


BEGIN
Writeln('BIG_MESS.PAS   www.merlyn.demon.co.uk  >= 2000-07-28') ;
if ParamCount>0 then begin
  Val(ParamStr(1), Over, J) ;
  if J<>0 then begin
    Writeln('Bad number "', ParamStr(1), '", fail!') ; EXIT end ;
  end ;

N1 := 0 ; NM := 0 ;
Writeln('MIDno   At Line    Lines ', MID) ;

while not EoF do begin
  Readln(S1) ; Inc(N1) ;
  if Copy(S1, 1, Length(MID))=MID then begin
    MayWrite ; N2 := N1 ; S2 := S1 ; Inc(NM) end ;
  end ;

MayWrite ;
Writeln(NM:5, ' messages; OK.') ;
END.