diff --git a/src/binary-reversal/index.js b/src/binary-reversal/index.js
index 965bccf4..c2ac27d4 100644
--- a/src/binary-reversal/index.js
+++ b/src/binary-reversal/index.js
@@ -3,6 +3,41 @@
  *
  *  * @param {string} value
  */
-function binaryReversal(value) {}
+ function binaryReversal(value) {
+    let loop = Math.floor(value**0.5) + 1
+    let arr = []
+    for (let i = 0; i < loop; i++) {
+
+      if (value > 1) {
+        arr.push(value % 2)
+        value = Math.floor(value/2)
+      } else if (value == 1) {
+        arr.push(1)
+        value = 0
+      }
+    }
+    console.log(arr);
+    let strNum = arr.join('')
+    let length = strNum.length
+
+    let n8 = Math.ceil(length/8)
+
+    if (length < (8 * n8)) {
+      let diff = (8 * n8) - strNum.length;
+      
+      for (let i = 0; i < diff; i++) {
+        strNum += '0'
+      }
+    }
+    let newLength = strNum.length
+   
+    let sumArray = []
+    for (let i = 0; i < newLength; i++) {
+      let pow = newLength - 1 - i
+      let num = strNum[i]
+      sumArray.push(num * (2**pow))
+    }
+    return sumArray.reduce((a, b) => a + b).toString();
+  }
 
 module.exports = binaryReversal;
diff --git a/src/list-sorting/index.js b/src/list-sorting/index.js
index 6636c20d..b56a0c69 100644
--- a/src/list-sorting/index.js
+++ b/src/list-sorting/index.js
@@ -1,3 +1,39 @@
-function listSorting(needle, haystack) {}
+function listSorting(needle, haystack) {
+    if (haystack.length == 0) return -1
+
+    let arr = [];
+
+    if (typeof(haystack[0]) == 'object') {
+
+      for (let i = 0; i < haystack.length; i++) {
+        if(haystack[i].length != 0 && haystack[i].lastIndexOf(needle) != -1) {
+            arr.push(haystack[i].lastIndexOf(needle))
+        } else {
+            arr.push(null)
+        }
+      }
+
+      arr
+      if (arr.every((el) => el == null)) return -1
+
+      let arr2 = []
+      
+      for (let i = 0; i < arr.length; i++) {
+          let arr1 = []
+        if (typeof(arr[i]) == 'number') {
+            arr1.push(arr.lastIndexOf(arr[i]), arr[i])
+        } else continue
+        arr2.push(arr1)
+      }
+
+      arr2
+      if (arr2.length == 0) return -1
+      return arr2[arr2.length-1]
+    } else if (typeof(haystack[0]) == 'number') {
+      return haystack.lastIndexOf(needle)
+    }
+}
+
+
 
 module.exports = listSorting;