CREATE TABLE Person (
  name varchar(20) PRIMARY KEY,
  age INTEGER,
  city TEXT,
  gender TEXT,
  job TEXT
)

CREATE TABLE PersonFriend (
  name varchar(20),
  friend varchar(20),
  year INTEGER,
  FOREIGN KEY (name) REFERENCES Person(name),
  FOREIGN KEY (friend) REFERENCES Person(name)
)
SELECT T1.age FROM Person AS T1 JOIN PersonFriend AS T2 ON T1.name  =  T2.friend WHERE T2.name =  'Zach' AND T2.year  =  (SELECT max(YEAR) FROM PersonFriend WHERE name =  'Zach')
What is the age of the friend of Zach with longest year relationship?