diff --git a/lib.js b/lib.js
index 60f30ab..18dd22e 100644
--- a/lib.js
+++ b/lib.js
@@ -7,9 +7,119 @@
  * @param {Filter} filter
  */
 function Iterator(friends, filter) {
-    console.info(friends, filter);
+    if (!(filter instanceof Filter)) {
+        throw new TypeError();
+    }
+    this.friends = friends;
+    this.map = {};
+    for (let friend of friends) {
+        this.map[friend.name] = friend;
+    }
+    this.current = friends.filter(f => f.best === true);
+    this.index = 0;
+    this.future = [];
+    this.returns = [];
+    this.filter = filter;
+    this.best = [];
+    this.other = [[]];
+    this.was = false;
+
 }
 
+Object.assign(Iterator.prototype, {
+
+    kek() {
+        this.prepare();
+        let comparator = (f1, f2) => {
+            if (f1.name > f2.name) {
+                return 1;
+            }
+            if (f1.name < f2.name) {
+                return -1;
+            }
+
+            return 0;
+        };
+        let copy = [];
+        this.best.sort(comparator);
+        for (let i = 0; i < this.other.length; i++) {
+            let arr = this.other[i];
+            arr.sort(comparator);
+            copy = copy.concat(arr);
+        }
+        this.other = copy;
+        this.other.reverse();
+        this.was = true;
+    },
+    done() {
+        if (!this.was) {
+            this.kek();
+        }
+
+        return this.best.length === 0 && this.other.length === 0;
+    },
+    next() {
+        if (!this.was) {
+            this.kek();
+        }
+        if (this.best.length !== 0) {
+            return this.best.pop();
+        }
+        if (this.other.length !== 0) {
+            return this.other.pop();
+        }
+
+        return null;
+    },
+
+    stop() {
+        this.checkoutCurrentIfNeed();
+
+        return this.current.length === 0;
+    },
+
+    add(friend) {
+        if (friend.best) {
+            this.best.push(friend);
+        } else {
+            this.other[this.other.length - 1].push(friend);
+        }
+    },
+    prepare() {
+        while (!this.stop()) {
+            let friend = this.current[this.index];
+            this.addFriendsInNext(friend);
+            this.returns.push(friend);
+            this.index++;
+            if (this.filter.apply(friend)) {
+                this.add(friend);
+            }
+
+        }
+    },
+    addFriendsInNext(friend) {
+        for (let friendName of friend.friends) {
+            let friend2 = this.map[friendName];
+            if (!this.returns.includes(friend2) && !this.current.includes(friend2) &&
+                !this.future.includes(friend2)) {
+                this.future.push(friend2);
+            }
+        }
+    },
+    checkoutCurrentIfNeed() {
+        if (this.index === this.current.length) {
+            if (this.future.length === 0) {
+                this.current = [];
+            } else {
+                this.current = this.future;
+                this.future = [];
+            }
+            this.index = 0;
+            this.other.push([]);
+        }
+    }
+});
+
 /**
  * Итератор по друзям с ограничением по кругу
  * @extends Iterator
@@ -19,15 +129,59 @@ function Iterator(friends, filter) {
  * @param {Number} maxLevel – максимальный круг друзей
  */
 function LimitedIterator(friends, filter, maxLevel) {
-    console.info(friends, filter, maxLevel);
+    this.check(filter);
+    this.friends = friends;
+    this.map = {};
+    for (let friend of friends) {
+        this.map[friend.name] = friend;
+    }
+    this.current = friends.filter(f => f.best === true);
+    this.index = 0;
+    this.future = [];
+    this.returns = [];
+    this.filter = filter;
+    this.best = [];
+    this.other = [[]];
+    this.was = false;
+    this.maxLevel = maxLevel;
+    this.level = 1;
 }
 
+Object.assign(LimitedIterator.prototype, Iterator.prototype, {
+    check(filter) {
+        if (!(filter instanceof Filter)) {
+            throw new TypeError();
+        }
+    },
+    stop() {
+        this.checkoutCurrentIfNeed();
+
+        return this.current.length === 0 || this.level > this.maxLevel;
+    },
+
+    checkoutCurrentIfNeed() {
+        if (this.index === this.current.length) {
+            if (this.future.length === 0) {
+                this.current = [];
+            } else {
+                this.current = this.future;
+                this.future = [];
+            }
+            this.index = 0;
+            this.other.push([]);
+            this.level++;
+        }
+    }
+});
+
 /**
  * Фильтр друзей
  * @constructor
  */
 function Filter() {
-    console.info('Filter');
+    this.apply = function (friend) {
+        return friend.hasOwnProperty('name');
+    };
 }
 
 /**
@@ -36,8 +190,12 @@ function Filter() {
  * @constructor
  */
 function MaleFilter() {
-    console.info('MaleFilter');
+    this.apply = function (friend) {
+        return friend.gender === 'male';
+    };
 }
+MaleFilter.prototype = Object.create(Filter.prototype);
+
 
 /**
  * Фильтр друзей-девушек
@@ -45,8 +203,11 @@ function MaleFilter() {
  * @constructor
  */
 function FemaleFilter() {
-    console.info('FemaleFilter');
+    this.apply = function (friend) {
+        return friend.gender === 'female';
+    };
 }
+FemaleFilter.prototype = Object.create(Filter.prototype);
 
 exports.Iterator = Iterator;
 exports.LimitedIterator = LimitedIterator;