title: How to use biginteger in Clojure?
body: <p>I am trying to calculate the 500th Fibonacci number in Clojure:</p>
  
  <pre><code>(defn fib-pair [[a b]] [b (+ a b)])
  (nth (map first (iterate fib-pair [1 1])) 500)
  ArithmeticException integer overflow  clojure.lang.Numbers.throwIntOverflow (Numbers.java:1388)
  </code></pre>
  
  <p>This program failed because the number is too big: integer overflow. How to solve this problem?</p>