diff --git a/03week/towersOfHanoi.js b/03week/towersOfHanoi.js
index 3cf6df049..2b9f24fd7 100644
--- a/03week/towersOfHanoi.js
+++ b/03week/towersOfHanoi.js
@@ -1,94 +1,109 @@
-'use strict';
+"use strict";
 
-const assert = require('assert');
-const readline = require('readline');
+const assert = require("assert");
+const readline = require("readline");
 const rl = readline.createInterface({
-  input: process.stdin,
-  output: process.stdout
+input: process.stdin,
+output: process.stdout
 });
 
 let stacks = {
-  a: [4, 3, 2, 1],
-  b: [],
-  c: []
+a: [4, 3, 2, 1],
+b: [],
+c: []
 };
 
 function printStacks() {
-  console.log("a: " + stacks.a);
-  console.log("b: " + stacks.b);
-  console.log("c: " + stacks.c);
+console.log("a: " + stacks.a);
+console.log("b: " + stacks.b);
+console.log("c: " + stacks.c);
 }
 
-function movePiece() {
-  // Your code here
-
+function movePiece(startStack, endStack) {
+stacks[endStack].push(stacks[startStack].pop());
 }
 
-function isLegal() {
-  // Your code here
-
+function isLegal(startStack, endStack) {
+if (
+stacks[startStack][stacks[startStack].length - 1] === undefined &&
+stacks[startStack][stacks[endStack].length - 1] === undefined
+) {
+return false;
+} else if (
+stacks[startStack][stacks[startStack].length - 1] <
+stacks[endStack][stacks[endStack].length - 1] ||
+stacks[endStack][stacks[endStack].length - 1] === undefined
+) {
+return true;
+} else {
+console.log("Invalid move");
+return false;
+}
 }
 
 function checkForWin() {
-  // Your code here
-
+if (stacks.b.length === 4) {
+return true;
+} else {
+return false;
+}
 }
 
 function towersOfHanoi(startStack, endStack) {
-  // Your code here
-
+let newStart = startStack.toLowerCase().trim();
+let newEnd = endStack.toLowerCase().trim();
+if (isLegal(startStack, endStack)) {
+movePiece(newStart, newEnd);
+checkForWin();
+}
 }
 
 function getPrompt() {
-  printStacks();
-  rl.question('start stack: ', (startStack) => {
-    rl.question('end stack: ', (endStack) => {
-      towersOfHanoi(startStack, endStack);
-      getPrompt();
-    });
-  });
+printStacks();
+rl.question("start stack: ", startStack => {
+rl.question("end stack: ", endStack => {
+towersOfHanoi(startStack, endStack);
+getPrompt();
+});
+});
 }
 
 // Tests
 
-if (typeof describe === 'function') {
-
-  describe('#towersOfHanoi()', () => {
-    it('should be able to move a block', () => {
-      towersOfHanoi('a', 'b');
-      assert.deepEqual(stacks, { a: [4, 3, 2], b: [1], c: [] });
-    });
-  });
-
-  describe('#isLegal()', () => {
-    it('should not allow an illegal move', () => {
-      stacks = {
-        a: [4, 3, 2],
-        b: [1],
-        c: []
-      };
-      assert.equal(isLegal('a', 'b'), false);
-    });
-    it('should allow a legal move', () => {
-      stacks = {
-        a: [4, 3, 2, 1],
-        b: [],
-        c: []
-      };
-      assert.equal(isLegal('a', 'c'), true);
-    });
-  });
-  describe('#checkForWin()', () => {
-    it('should detect a win', () => {
-      stacks = { a: [], b: [4, 3, 2, 1], c: [] };
-      assert.equal(checkForWin(), true);
-      stacks = { a: [1], b: [4, 3, 2], c: [] };
-      assert.equal(checkForWin(), false);
-    });
-  });
+if (typeof describe === "function") {
+describe("#towersOfHanoi()", () => {
+it("should be able to move a block", () => {
+towersOfHanoi("a", "b");
+assert.deepEqual(stacks, { a: [4, 3, 2], b: [1], c: [] });
+});
+});
 
+describe("#isLegal()", () => {
+it("should not allow an illegal move", () => {
+stacks = {
+a: [4, 3, 2],
+b: [1],
+c: []
+};
+assert.equal(isLegal("a", "b"), false);
+});
+it("should allow a legal move", () => {
+stacks = {
+a: [4, 3, 2, 1],
+b: [],
+c: []
+};
+assert.equal(isLegal("a", "c"), true);
+});
+});
+describe("#checkForWin()", () => {
+it("should detect a win", () => {
+stacks = { a: [], b: [4, 3, 2, 1], c: [] };
+assert.equal(checkForWin(), true);
+stacks = { a: [1], b: [4, 3, 2], c: [] };
+assert.equal(checkForWin(), false);
+});
+});
 } else {
-
-  getPrompt();
-
-}
+getPrompt();
+}
\ No newline at end of file