diff --git a/src/main/java/part2/cache/CachingDataStorageImpl.java b/src/main/java/part2/cache/CachingDataStorageImpl.java
index a2ae460..ede9905 100755
--- a/src/main/java/part2/cache/CachingDataStorageImpl.java
+++ b/src/main/java/part2/cache/CachingDataStorageImpl.java
@@ -1,5 +1,6 @@
 package part2.cache;
 
+import com.sun.javafx.geom.AreaOp;
 import db.DataStorage;
 import db.SlowCompletableFutureDb;
 
@@ -38,6 +39,30 @@ public OutdatableResult<T> getOutdatable(String key) {
         // TODO don't use obtrudeException on result - just don't
         // TODO use remove(Object key, Object value) to remove target value
         // TODO Start timeout after receiving result in CompletableFuture, not after receiving CompletableFuture itself
-        throw new UnsupportedOperationException();
+
+        OutdatableResult<T> res = new OutdatableResult<>(new CompletableFuture<>(), new CompletableFuture<>());
+        OutdatableResult<T> tOutdatableResult = cache.putIfAbsent(key, res);
+
+        if (tOutdatableResult == null) {
+            db.get(key).whenComplete(
+                    (t, e) -> {
+                        scheduledExecutorService.schedule(() -> {
+                                    cache.remove(key, cache.get(key));
+                                    res.getOutdated().complete(null);
+                                },
+                                timeout,
+                                timeoutUnits
+                        );
+                        if (e != null) {
+                            res.getResult().completeExceptionally(e);
+                        } else {
+                            res.getResult().complete(t);
+                        }
+                    }
+            );
+            return res;
+        } else {
+            return tOutdatableResult;
+        }
     }
 }
diff --git a/src/main/java/part3/exercise/ComposeCachingDataStorage.java b/src/main/java/part3/exercise/ComposeCachingDataStorage.java
index 64d1b3d..4d71987 100755
--- a/src/main/java/part3/exercise/ComposeCachingDataStorage.java
+++ b/src/main/java/part3/exercise/ComposeCachingDataStorage.java
@@ -2,20 +2,55 @@
 
 import part2.cache.CachingDataStorage;
 
+import java.util.concurrent.CompletableFuture;
 import java.util.function.Function;
 
 public class ComposeCachingDataStorage<K1, T1, K2, T2> implements CachingDataStorage<K1, T2> {
 
-    public ComposeCachingDataStorage(CachingDataStorage<K1, T1> storage1,
-                                     CachingDataStorage<K2, T2> storage2,
-                                     Function<T1, K2> mapping) {
-        // TODO
-        throw new UnsupportedOperationException();
+    private CachingDataStorage<K1, T1> storage1;
+    private CachingDataStorage<K2, T2> storage2;
+    private Function<T1, K2> mapping;
+
+    public ComposeCachingDataStorage(CachingDataStorage<K1, T1> storage1, CachingDataStorage<K2, T2> storage2, Function<T1, K2> mapping) {
+        this.storage1 = storage1;
+        this.storage2 = storage2;
+        this.mapping = mapping;
     }
 
     @Override
     public OutdatableResult<T2> getOutdatable(K1 key) {
-        // TODO
-        throw new UnsupportedOperationException();
+
+        OutdatableResult<T1> outdatableFromStorage1 = storage1.getOutdatable(key);
+
+        CompletableFuture<OutdatableResult<T2>> outdatableResultCompletableFuture = outdatableFromStorage1.getResult().thenApply(
+                v -> storage2.getOutdatable(mapping.apply(v))
+        );
+
+        OutdatableResult<T2> result = new OutdatableResult<>(new CompletableFuture<>(), new CompletableFuture<>());
+
+        thenComplete(outdatableFromStorage1.getOutdated(), result.getOutdated());
+        outdatableResultCompletableFuture.thenAccept(
+                v -> v.getResult().thenAccept(
+                        res -> {
+                            result.getResult().complete(res);
+                            thenComplete(v.getOutdated(),result.getOutdated());
+                        }
+                )
+        );
+
+        return result;
+    }
+
+    private void thenComplete(CompletableFuture<Void> source, CompletableFuture<Void> target) {
+        source.whenComplete(
+                (r,e) -> {
+                    if (e == null) {
+                        target.complete(null);
+                    } else {
+                        target.completeExceptionally(e);
+                    }
+                }
+        );
     }
+
 }
diff --git a/src/main/java/part3/exercise/ListCachingDataStorage.java b/src/main/java/part3/exercise/ListCachingDataStorage.java
index bb47836..ea99fb6 100755
--- a/src/main/java/part3/exercise/ListCachingDataStorage.java
+++ b/src/main/java/part3/exercise/ListCachingDataStorage.java
@@ -3,17 +3,50 @@
 import part2.cache.CachingDataStorage;
 
 import java.util.List;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
+import java.util.stream.Collectors;
 
 public class ListCachingDataStorage<K, T> implements CachingDataStorage<List<K>, List<T>> {
 
+    private CachingDataStorage<K,T> storage;
+
     public ListCachingDataStorage(CachingDataStorage<K, T> storage) {
-        // TODO
-        throw new UnsupportedOperationException();
+        this.storage = storage;
     }
 
     @Override
     public OutdatableResult<List<T>> getOutdatable(List<K> key) {
-        // TODO
-        throw new UnsupportedOperationException();
+        List<OutdatableResult<T>> collect = key.stream()
+                .map(storage::getOutdatable)
+                .collect(Collectors.toList());
+
+        List<CompletableFuture<Void>> outdatables = collect.stream()
+                .map(OutdatableResult::getOutdated)
+                .collect(Collectors.toList());
+
+        List<CompletableFuture<T>> results = collect.stream()
+                .map(OutdatableResult::getResult)
+                .collect(Collectors.toList());
+
+        CompletableFuture<List<T>> listCompletableFuture = CompletableFuture.allOf(results.toArray(new CompletableFuture[0]))
+                .thenApply(v -> results.stream()
+                        .map(ListCachingDataStorage::getOrNull)
+                        .collect(Collectors.toList()));
+
+        return new OutdatableResult<>(
+                listCompletableFuture,
+                CompletableFuture.anyOf(outdatables.toArray(new CompletableFuture[0])).thenApply(v -> null)
+        );
+    }
+
+    private static <T> T getOrNull(Future<T> f) {
+        try {
+            return f.get();
+        } catch (InterruptedException | ExecutionException e1) {
+            e1.printStackTrace();
+            return null;
+        }
     }
 }
diff --git a/src/main/java/part3/exercise/MappingCachingDataStorage.java b/src/main/java/part3/exercise/MappingCachingDataStorage.java
index 39ef5ea..64db106 100755
--- a/src/main/java/part3/exercise/MappingCachingDataStorage.java
+++ b/src/main/java/part3/exercise/MappingCachingDataStorage.java
@@ -7,16 +7,23 @@
 
 public class MappingCachingDataStorage<K, K1, T1, T> implements CachingDataStorage<K, T> {
 
-    public MappingCachingDataStorage(CachingDataStorage<K1, T1> storage,
-                                     Function<K, K1> mapKey,
-                                     BiFunction<K, T1, T> mapValue) {
-        // TODO
-        throw new UnsupportedOperationException();
+    private CachingDataStorage<K1, T1> storage;
+    private Function<K, K1> mapKey;
+    private BiFunction<K, T1, T> mapValue;
+
+    public MappingCachingDataStorage(CachingDataStorage<K1, T1> storage, Function<K, K1> mapKey, BiFunction<K, T1, T> mapValue) {
+        this.storage = storage;
+        this.mapKey = mapKey;
+        this.mapValue = mapValue;
     }
 
     @Override
     public OutdatableResult<T> getOutdatable(K key) {
-        // TODO
-        throw new UnsupportedOperationException();
+        OutdatableResult<T1> outdatable = storage.getOutdatable(mapKey.apply(key));
+
+        return new OutdatableResult<>(
+                outdatable.getResult().thenApply(t1 -> mapValue.apply(key, t1)),
+                outdatable.getOutdated()
+        );
     }
 }
diff --git a/src/main/java/part3/exercise/PairCachingDataStorage.java b/src/main/java/part3/exercise/PairCachingDataStorage.java
index fa3a735..4f0a8d7 100755
--- a/src/main/java/part3/exercise/PairCachingDataStorage.java
+++ b/src/main/java/part3/exercise/PairCachingDataStorage.java
@@ -2,23 +2,41 @@
 
 import part2.cache.CachingDataStorage;
 
+import java.util.concurrent.CompletableFuture;
 import java.util.function.BiFunction;
 import java.util.function.Function;
 
 public class PairCachingDataStorage<K, T, K1, T1, K2, T2> implements CachingDataStorage<K, T> {
 
-    public PairCachingDataStorage(CachingDataStorage<K1, T1> storage1,
-                                  CachingDataStorage<K2, T2> storage2,
-                                  Function<K, K1> getKey1,
-                                  Function<K, K2> getKey2,
-                                  Function<K, BiFunction<T1, T2, T>> resultMapper) {
-        // TODO
-        throw new UnsupportedOperationException();
+    private CachingDataStorage<K1, T1> storage1;
+    private CachingDataStorage<K2, T2> storage2;
+    private Function<K, K1> getKey1;
+    private Function<K, K2> getKey2;
+    private Function<K, BiFunction<T1, T2, T>> resultMapper;
+
+
+    public PairCachingDataStorage(
+            CachingDataStorage<K1, T1> storage1,
+            CachingDataStorage<K2, T2> storage2,
+            Function<K, K1> getKey1,
+            Function<K, K2> getKey2,
+            Function<K, BiFunction<T1, T2, T>> resultMapper
+    ) {
+        this.storage1 = storage1;
+        this.storage2 = storage2;
+        this.getKey1 = getKey1;
+        this.getKey2 = getKey2;
+        this.resultMapper = resultMapper;
     }
 
     @Override
     public OutdatableResult<T> getOutdatable(K key) {
-        // TODO
-        throw new UnsupportedOperationException();
+        OutdatableResult<T1> outdatable1 = storage1.getOutdatable(getKey1.apply(key));
+        OutdatableResult<T2> outdatable2 = storage2.getOutdatable(getKey2.apply(key));
+
+        return new OutdatableResult<>(
+                outdatable1.getResult().thenCombine(outdatable2.getResult(), resultMapper.apply(key)),
+                CompletableFuture.anyOf(outdatable1.getOutdated(),outdatable2.getOutdated()).thenApply(v -> null)
+        );
     }
 }