public static void main ( String [ ] args ) {
  Scanner sc = new Scanner ( System . in ) ;
  String S = sc . next ( ) ;
  List < String > sList = Arrays . asList ( S . split ( "" ) ) ;
  int zeroCount = 0 ;
  int oneCount = 0 ;
  int ans = 0 ;
  for ( String s : sList ) {
    if ( s . equals ( "0" ) ) {
      zeroCount ++ ;
    }
    else {
      oneCount ++ ;
    }
  }
  if ( zeroCount > oneCount ) {
    ans = oneCount * 2 ;
  }
  else {
    ans = zeroCount * 2 ;
  }
  System . out . println ( ans ) ;
}

public static void main ( String [ ] args ) { Scanner sc = new Scanner ( System . in ) ; String S = sc . next ( ) ; List < String > sList = Arrays . asList ( S . split ( " " ) ) ; int zeroCount = 0 ; int oneCount = 0 ; int ans = 0 ; for ( String s : sList ) { if ( s . equals ( "0" ) ) { zeroCount ++ ; } else { oneCount ++ ; } } if ( zeroCount > oneCount ) { ans = oneCount * 2 ; } else { ans = zeroCount * 2 ; } System . out . println ( ans ) ; }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (array_type element: (type_identifier) dimensions: (dimensions)) name: (identifier))) body: (block (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (type_identifier) arguments: (argument_list (field_access object: (identifier) field: (identifier)))))) (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (local_variable_declaration type: (generic_type (type_identifier) (type_arguments (type_identifier))) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (string_literal))))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (enhanced_for_statement type: (type_identifier) name: (identifier) value: (identifier) body: (block (if_statement condition: (parenthesized_expression (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (string_literal)))) consequence: (block (expression_statement (update_expression (identifier)))) alternative: (block (expression_statement (update_expression (identifier))))))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) consequence: (block (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (identifier) right: (decimal_integer_literal))))) alternative: (block (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (identifier) right: (decimal_integer_literal)))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))