public static void main ( String [ ] args ) {
  sc = new Scanner ( System . in ) ;
  int N = sc . nextInt ( ) ;
  int max_dist = - 1 ;
  int max_node = - 1 ;
  for ( int i = 2 ;
  i <= N ;
  i ++ ) {
    int dist = getDist ( 1 , i ) ;
    if ( max_dist < dist ) {
      max_dist = dist ;
      max_node = i ;
    }
  }
  int ans = - 1 ;
  for ( int i = 1 ;
  i <= N ;
  i ++ ) {
    if ( i == max_node ) continue ;
    ans = Math . max ( ans , getDist ( max_node , i ) ) ;
  }
  System . out . println ( "! " + ans ) ;
}

public static void main ( String [ ] args ) { sc = new Scanner ( System . in ) ; int N = sc . nextInt ( ) ; int max_dist = - 1 ; int max_node = - 1 ; for ( int i = 2 ; i <= N ; i ++ ) { int dist = getDist ( 1 , i ) ; if ( max_dist < dist ) { max_dist = dist ; max_node = i ; } } int ans = - 1 ; for ( int i = 1 ; i <= N ; i ++ ) { if ( i == max_node ) continue ; ans = Math . max ( ans , getDist ( max_node , i ) ) ; } 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 (expression_statement (assignment_expression left: (identifier) right: (object_creation_expression type: (type_identifier) arguments: (argument_list (field_access object: (identifier) field: (identifier)))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (unary_expression operand: (decimal_integer_literal)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (unary_expression operand: (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: (identifier)) update: (update_expression (identifier)) body: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation name: (identifier) arguments: (argument_list (decimal_integer_literal) (identifier))))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) consequence: (block (expression_statement (assignment_expression left: (identifier) right: (identifier))) (expression_statement (assignment_expression left: (identifier) right: (identifier))))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (unary_expression operand: (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: (identifier)) update: (update_expression (identifier)) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) consequence: (continue_statement)) (expression_statement (assignment_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier) (method_invocation name: (identifier) arguments: (argument_list (identifier) (identifier))))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (binary_expression left: (string_literal) right: (identifier)))))))