diff --git a/app.js b/app.js
index ad9a93a..42c55b4 100644
--- a/app.js
+++ b/app.js
@@ -1 +1,17 @@
-'use strict';
+'use strict'
+const memo = new Map()
+memo.set(0, 0)
+memo.set(1, 0)
+memo.set(2, 1)
+function fib(n) {
+  if (memo.has(n)) {
+    return memo.get(n)
+  }
+  const value = fib(n - 1) + fib(n - 2) + fib(n - 3)
+  memo.set(n, value)
+  return value
+}
+const length = 40
+for (let i = 0; i <= length; i++) {
+  console.log(fib(i))
+}