public static void main ( String [ ] args ) {
  Scanner scan = new Scanner ( System . in ) ;
  long A = scan . nextLong ( ) ;
  long B = scan . nextLong ( ) ;
  long [ ] two = new long [ 61 ] ;
  two [ 0 ] = 1 ;
  for ( int i = 1 ;
  i < 61 ;
  i ++ ) {
    two [ i ] = two [ i - 1 ] * 2 ;
  }
  int maxk = 0 ;
  out : for ( int j = 60 ;
  j >= 0 ;
  j -- ) {
    for ( int i = j ;
    i >= 0 ;
    i -- ) {
      if ( A <= two [ i ] && B >= two [ i ] ) {
        maxk = i ;
        break out ;
      }
      if ( i == 0 ) {
        for ( int k = 1 ;
        k <= 60 ;
        k ++ ) {
          if ( A < two [ k ] ) {
            A -= two [ k - 1 ] ;
            B -= two [ k - 1 ] ;
            break ;
          }
        }
      }
    }
  }
  long ans = two [ maxk ] - A ;
  B -= two [ maxk ] ;
  int maxk_ = 0 ;
  for ( int i = 0 ;
  i <= 60 ;
  i ++ ) {
    if ( B < two [ i ] ) {
      maxk_ = i ;
      break ;
    }
  }
  ans += two [ maxk_ ] ;
  if ( two [ maxk_ ] <= A ) {
    ans += two [ maxk ] - A ;
  }
  else {
    ans += two [ maxk ] - two [ maxk_ ] ;
  }
  System . out . println ( ans ) ;
}

public static void main ( String [ ] args ) { Scanner scan = new Scanner ( System . in ) ; long A = scan . nextLong ( ) ; long B = scan . nextLong ( ) ; long [ ] two = new long [ 61 ] ; two [ 0 ] = 1 ; for ( int i = 1 ; i < 61 ; i ++ ) { two [ i ] = two [ i - 1 ] * 2 ; } int maxk = 0 ; out : for ( int j = 60 ; j >= 0 ; j -- ) { for ( int i = j ; i >= 0 ; i -- ) { if ( A <= two [ i ] && B >= two [ i ] ) { maxk = i ; break out ; } if ( i == 0 ) { for ( int k = 1 ; k <= 60 ; k ++ ) { if ( A < two [ k ] ) { A -= two [ k - 1 ] ; B -= two [ k - 1 ] ; break ; } } } } } long ans = two [ maxk ] - A ; B -= two [ maxk ] ; int maxk_ = 0 ; for ( int i = 0 ; i <= 60 ; i ++ ) { if ( B < two [ i ] ) { maxk_ = i ; break ; } } ans += two [ maxk_ ] ; if ( two [ maxk_ ] <= A ) { ans += two [ maxk ] - A ; } else { ans += two [ maxk ] - two [ maxk_ ] ; } System . out . println ( ans ) ; }
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left: (identifier) right: (decimal_integer_literal))))) (break_statement)))))))))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (identifier)))) (expression_statement (assignment_expression left: (identifier) right: (array_access array: (identifier) index: (identifier)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (decimal_integer_literal)) update: (update_expression (identifier)) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (array_access array: (identifier) index: 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(argument_list (identifier))))))