System send, "Wrong Answer" test # 3! Why? And if replace (N1 > N2)- (N1 >= N2) OK?

PROGRAM B;

{$APPTYPE CONSOLE}

uses
  SYSUTILS;

VAR
  Mas1, Mas2 : ARRAY[1..50000] OF INTEGER;
  j : INTEGER;
  N1, N2 : INTEGER;
  Flag2 : BOOLEAN;
  Net : BOOLEAN;

PROCEDURE Search(Flag : BOOLEAN; L, R : INTEGER);

VAR
  C : INTEGER;

BEGIN
  WHILE ((L <= R) AND (Flag2 = FALSE) AND (Net = FALSE)) DO
    BEGIN
      C := ((L + R) DIV 2);
      IF Flag THEN
        BEGIN
          IF ((Mas2[j] + Mas1[C]) = 10000) THEN
            Flag2 := TRUE
          ELSE
            BEGIN
              IF ((Mas2[j] + Mas1[C]) > 10000) THEN
                Search(TRUE, L, (C - 1))
              ELSE
                Search(TRUE, (C + 1), R);
            END;
          Net := TRUE;
        END
      ELSE
        BEGIN
          IF ((Mas1[j] + Mas2[C]) = 10000) THEN
            Flag2 := TRUE
          ELSE
            BEGIN
              IF ((Mas1[j] + Mas2[C]) > 10000) THEN
                Search(TRUE, L, (C - 1))
              ELSE
                Search(TRUE, (C + 1), R);
            END;
          Net := TRUE;
        END;
    END;
END;

BEGIN
  {$IFNDEF ONLINE_JUDGE}
  ASSIGNFILE(INPUT, 'Input.txt');
  ASSIGNFILE(OUTPUT, 'Output.txt');
  {$ENDIF}

  RESET(INPUT);
  REWRITE(OUTPUT);

  ReadLn(Input, N1);

  FOR j := 1 TO N1 DO
    ReadLn(Input, Mas1[j]);

  ReadLn(Input, N2);

  FOR j := 1 TO (N2 - 1) DO
    ReadLn(Input, Mas2[j]);
  Read(Input, Mas2[N2]);

  j := 1;
  Net := FALSE;

  IF (N1 > N2) THEN
    BEGIN
      REPEAT
        Flag2 := FALSE;
        Search(TRUE, 1, N1);
        j := j + 1;
        Net := FALSE;
      UNTIL (Flag2 OR (j > N2));
    END
  ELSE
     BEGIN
      REPEAT
        Flag2 := FALSE;
        Search(FALSE, 1, N2);
        j := j + 1;
        Net := FALSE;
      UNTIL (Flag2 OR (j > N1));
    END;

  IF (Flag2 = TRUE) THEN
    Write(Output, 'YES')
  ELSE
    Write(Output, 'NO');

  {$IFNDEF ONLINE_JUDGE}
  CLOSE(INPUT);
  CLOSE(OUTPUT);
  {$ENDIF}
END.

Edited by author 05.11.2008 15:02