public static void main ( String [ ] args ) {
  FastScanner scan = new FastScanner ( ) ;
  int n = scan . nextInt ( ) ;
  double ans = 0 ;
  while ( n > 0 ) {
    double temp = ( double ) 1 / n ;
    ans += temp ;
    n -- ;
  }
  System . out . println ( ans ) ;
}

public static void main ( String [ ] args ) { FastScanner scan = new FastScanner ( ) ; int n = scan . nextInt ( ) ; double ans = 0 ; while ( n > 0 ) { double temp = ( double ) 1 / n ; ans += temp ; n -- ; } 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)))) (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: (floating_point_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (while_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) body: (block (local_variable_declaration type: (floating_point_type) declarator: (variable_declarator name: (identifier) value: (binary_expression left: (cast_expression type: (floating_point_type) value: (decimal_integer_literal)) right: (identifier)))) (expression_statement (assignment_expression left: (identifier) right: (identifier))) (expression_statement (update_expression (identifier))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))