public static void main ( String [ ] args ) {
  Scanner reader = new Scanner ( System . in ) ;
  int home = reader . nextInt ( ) ;
  double interm = - 0.5 + Math . sqrt ( 0.25 + 2 * home ) ;
  if ( interm % 1.0 > 0 ) {
    System . out . println ( ( int ) ( interm + 1 ) ) ;
  }
  else {
    System . out . println ( ( int ) interm ) ;
  }
}

public static void main ( String [ ] args ) { Scanner reader = new Scanner ( System . in ) ; int home = reader . nextInt ( ) ; double interm = - 0.5 + Math . sqrt ( 0.25 + 2 * home ) ; if ( interm % 1.0 > 0 ) { System . out . println ( ( int ) ( interm + 1 ) ) ; } else { System . out . println ( ( int ) interm ) ; } }
(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: (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: (binary_expression left: (unary_expression operand: (decimal_floating_point_literal)) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (binary_expression left: (decimal_floating_point_literal) right: (binary_expression left: (decimal_integer_literal) right: (identifier)))))))) (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (identifier) right: (decimal_floating_point_literal)) right: (decimal_integer_literal))) consequence: (block (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (cast_expression type: (integral_type) value: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal)))))))) alternative: (block (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (cast_expression type: (integral_type) value: (identifier)))))))))