static int sumEven ( int l , int r ) {
  return sumNatural ( r / 2 ) - sumNatural ( ( l - 1 ) / 2 ) ;
}

static int sumEven ( int l , int r ) { return sumNatural ( r / 2 ) - sumNatural ( ( l - 1 ) / 2 ) ; }
(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 (return_statement (binary_expression left: (method_invocation name: (identifier) arguments: (argument_list (binary_expression left: (identifier) right: (decimal_integer_literal)))) right: (method_invocation name: (identifier) arguments: (argument_list (binary_expression left: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (decimal_integer_literal))))))))