I tried many cases and got the same answers as another ACed program.
But I still got WA. Why?


{No.1064 Binary Search}
const
  MAXN = 10000;
var
  A: array[0..MAXN-1] of Longint;
  N,i,L: longint;
  Flag:Array[1..MAXN] Of Boolean;
  Duan,X,Y,Int1:LongInt;
  Bln1,IsFound:Boolean;
{-----Begin of original code-----}
procedure BinarySearch(x: LongInt);
var
  p, q, i: Longint;
begin
  p := 0;   { Left border of the search  }
  q := N-1; { Right border of the search }
  L := 0;   { Comparison counter         }
  while p <= q do begin
    i := (p + q) div 2;
    inc(L);
    if A[i] = x then begin
{      writeln('Found item i = ', i,
        ' in L = ', L, ' comparisons');}
      exit
    end;
    if x < A[i] then
      q := i - 1
    else
      p := i + 1
  end;
  IsFound:=False;
end;
{-----End of original code-----}
Begin
     ReadLn(X,Y);

     For i:=1 To MAXN Do
          A[i-1]:=i-1;
     FillChar(Flag,SizeOf(Flag),False);
     For N:=X To MAXN Do
     Begin
          IsFound:=True;
          BinarySearch(X);
          If Not IsFound Then Continue;
          If L=Y Then Flag[N]:=True;
     End;

     Duan:=0;
     Bln1:=False;
     For i:=1 To MAXN Do
     Begin
          If Flag[i] And Not Bln1 Then
               Inc(Duan);
          Bln1:=Flag[i];
     End;

     WriteLn(Duan);
     Int1:=-1;
     Bln1:=False;
     For i:=1 To MAXN Do
     Begin
          If Flag[i] And Not Bln1 Then
               Int1:=i;
          If Bln1 And Not Flag[i] Then
          Begin
               WriteLn(Int1,' ',i-1);
               Int1:=-1;
          End;
          Bln1:=Flag[i];
     End;
     If Flag[MAXN] Then
          WriteLn(Int1,' ',MAXN);
End.