static int multiply ( int x , int y ) {
  if ( y == 0 ) return 0 ;
  if ( y > 0 ) return ( x + multiply ( x , y - 1 ) ) ;
  if ( y < 0 ) return - multiply ( x , - y ) ;
  return - 1 ;
}

static int multiply ( int x , int y ) { if ( y == 0 ) return 0 ; if ( y > 0 ) return ( x + multiply ( x , y - 1 ) ) ; if ( y < 0 ) return - multiply ( x , - y ) ; return - 1 ; }
(method_declaration (modifiers) type: (integral_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (integral_type) name: (identifier)) (formal_parameter type: (integral_type) name: (identifier))) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) consequence: (return_statement (decimal_integer_literal))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) consequence: (return_statement (parenthesized_expression (binary_expression left: (identifier) right: (method_invocation name: (identifier) arguments: (argument_list (identifier) (binary_expression left: (identifier) right: (decimal_integer_literal)))))))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) consequence: (return_statement (unary_expression operand: (method_invocation name: (identifier) arguments: (argument_list (identifier) (unary_expression operand: (identifier))))))) (return_statement (unary_expression operand: (decimal_integer_literal)))))