CREATE OR REPLACE FUNCTION golden_ratio() RETURNS int AS
$$
DECLARE
golden1 INT;
golden2 INT;
sum INT;
first INT;
last INT;
indx INT;
prelast INT;
BEGIN
first := (SELECT number FROM nums WHERE id = 1);
indx := (SELECT max(id) FROM nums);
last := (SELECT number FROM nums WHERE id = indx);
prelast := (SELECT number FROM nums WHERE id = indx-1);
golden1 := ROUND((prelast*(3-5^0.5)/2));
golden2 := ROUND((last*(5^0,5-1)/2));
sum := first + last + golden1 + golden2;
RETURN sum;
END $$ LANGUAGE plpgsql;