public static void main ( String [ ] args ) {
  Scanner in = new Scanner ( System . in ) ;
  int [ ] places = {
    in . nextInt ( ) , in . nextInt ( ) , in . nextInt ( ) };
    int d = in . nextInt ( ) , c = 0 ;
    Arrays . sort ( places ) ;
    if ( places [ 1 ] - places [ 0 ] < d ) c = c + d - ( places [ 1 ] - places [ 0 ] ) ;
    if ( places [ 2 ] - places [ 1 ] < d ) c = c + d - ( places [ 2 ] - places [ 1 ] ) ;
    System . out . println ( c ) ;
  }
  
public static void main ( String [ ] args ) { Scanner in = new Scanner ( System . in ) ; int [ ] places = { in . nextInt ( ) , in . nextInt ( ) , in . nextInt ( ) } ; int d = in . nextInt ( ) , c = 0 ; Arrays . sort ( places ) ; if ( places [ 1 ] - places [ 0 ] < d ) c = c + d - ( places [ 1 ] - places [ 0 ] ) ; if ( places [ 2 ] - places [ 1 ] < d ) c = c + d - ( places [ 2 ] - places [ 1 ] ) ; System . out . println ( c ) ; }
(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: (array_type element: (integral_type) dimensions: (dimensions)) declarator: (variable_declarator name: (identifier) value: (array_initializer (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)) (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)) (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier)))) (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (array_access array: (identifier) index: (decimal_integer_literal)) right: (array_access array: (identifier) index: (decimal_integer_literal))) right: (identifier))) consequence: (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (decimal_integer_literal)) right: (array_access array: (identifier) index: (decimal_integer_literal)))))))) (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (array_access array: (identifier) index: (decimal_integer_literal)) right: (array_access array: (identifier) index: (decimal_integer_literal))) right: (identifier))) consequence: (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (decimal_integer_literal)) right: (array_access array: (identifier) index: (decimal_integer_literal)))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))