diff --git a/src/main/java/part3/exercise/ComposeCachingDataStorage.java b/src/main/java/part3/exercise/ComposeCachingDataStorage.java
index 64d1b3d..d59cbf2 100755
--- a/src/main/java/part3/exercise/ComposeCachingDataStorage.java
+++ b/src/main/java/part3/exercise/ComposeCachingDataStorage.java
@@ -2,20 +2,40 @@
 
 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> {
+    private final CachingDataStorage<K1, T1> storage1;
+    private final CachingDataStorage<K2, T2> storage2;
+    private final Function<T1, K2> mapping;
 
     public ComposeCachingDataStorage(CachingDataStorage<K1, T1> storage1,
                                      CachingDataStorage<K2, T2> storage2,
                                      Function<T1, K2> mapping) {
-        // TODO
-        throw new UnsupportedOperationException();
+        this.storage1 = storage1;
+        this.storage2 = storage2;
+        this.mapping = mapping;
     }
 
+
     @Override
     public OutdatableResult<T2> getOutdatable(K1 key) {
-        // TODO
-        throw new UnsupportedOperationException();
+        final OutdatableResult<T1> outdatable = storage1.getOutdatable(key);
+        final CompletableFuture<OutdatableResult<T2>> outdated
+                = outdatable.getResult().thenApply(v -> storage2.getOutdatable(mapping.apply(v)));
+
+        final OutdatableResult<T2> result
+                = new OutdatableResult<>(new CompletableFuture<>(), new CompletableFuture<>());
+
+        outdatable.getOutdated().thenAccept(v -> result.getOutdated().complete(v));
+
+        outdated.thenAccept(v -> {
+            v.getResult().thenAccept(t -> {
+                result.getResult().complete(t);
+                result.getOutdated().thenAccept(o -> result.getOutdated().complete(o));
+            });
+        });
+        return result;
     }
 }
diff --git a/src/main/java/part3/exercise/ListCachingDataStorage.java b/src/main/java/part3/exercise/ListCachingDataStorage.java
index bb47836..be942cb 100755
--- a/src/main/java/part3/exercise/ListCachingDataStorage.java
+++ b/src/main/java/part3/exercise/ListCachingDataStorage.java
@@ -3,17 +3,44 @@
 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 final CachingDataStorage<K, T> storage;
 
     public ListCachingDataStorage(CachingDataStorage<K, T> storage) {
-        // TODO
-        throw new UnsupportedOperationException();
+        this.storage = storage;
+    }
+
+    private <T> T getOrNull(Future<T> f) {
+        try {
+            return f.get();
+        } catch (InterruptedException | ExecutionException e1) {
+            e1.printStackTrace();
+            return null;
+        }
     }
 
     @Override
     public OutdatableResult<List<T>> getOutdatable(List<K> key) {
-        // TODO
-        throw new UnsupportedOperationException();
+        final List<OutdatableResult<T>> collect = key.stream()
+                .map(storage::getOutdatable)
+                .collect(Collectors.toList());
+
+        final CompletableFuture<Void> voidCompletableFuture = CompletableFuture.allOf(collect.stream()
+                .map(OutdatableResult::getResult)
+                .toArray(CompletableFuture[]::new));
+
+        return new OutdatableResult<>(voidCompletableFuture.thenApply(v -> collect.stream()
+                .map(OutdatableResult::getResult)
+                .map(this::getOrNull)
+                .collect(Collectors.toList())),
+                CompletableFuture.anyOf(collect.stream()
+                        .map(OutdatableResult::getOutdated)
+                        .toArray(CompletableFuture[]::new))
+                        .thenApply(v -> null));
     }
 }
diff --git a/src/main/java/part3/exercise/MappingCachingDataStorage.java b/src/main/java/part3/exercise/MappingCachingDataStorage.java
index 39ef5ea..1ca489c 100755
--- a/src/main/java/part3/exercise/MappingCachingDataStorage.java
+++ b/src/main/java/part3/exercise/MappingCachingDataStorage.java
@@ -6,17 +6,23 @@
 import java.util.function.Function;
 
 public class MappingCachingDataStorage<K, K1, T1, T> implements CachingDataStorage<K, T> {
+    private final CachingDataStorage<K1, T1> storage;
+    private final Function<K, K1> mapKey;
+    private final BiFunction<K, T1, T> mapValue;
 
     public MappingCachingDataStorage(CachingDataStorage<K1, T1> storage,
                                      Function<K, K1> mapKey,
                                      BiFunction<K, T1, T> mapValue) {
-        // TODO
-        throw new UnsupportedOperationException();
+        this.storage = storage;
+        this.mapKey = mapKey;
+        this.mapValue = mapValue;
     }
 
     @Override
     public OutdatableResult<T> getOutdatable(K key) {
-        // TODO
-        throw new UnsupportedOperationException();
+        final OutdatableResult<T1> outdatable = storage.getOutdatable(mapKey.apply(key));
+
+        return new OutdatableResult<>(outdatable.getResult().thenApply(v -> mapValue.apply(key, v)),
+                outdatable.getOutdated());
     }
 }
diff --git a/src/main/java/part3/exercise/PairCachingDataStorage.java b/src/main/java/part3/exercise/PairCachingDataStorage.java
index fa3a735..9b07d0b 100755
--- a/src/main/java/part3/exercise/PairCachingDataStorage.java
+++ b/src/main/java/part3/exercise/PairCachingDataStorage.java
@@ -2,23 +2,35 @@
 
 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> {
 
+    private final CachingDataStorage<K1, T1> storage1;
+    private final CachingDataStorage<K2, T2> storage2;
+    private final Function<K, K1> getKey1;
+    private final Function<K, K2> getKey2;
+    private final 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) {
-        // TODO
-        throw new UnsupportedOperationException();
+        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();
+        final OutdatableResult<T1> outdatable = storage1.getOutdatable(getKey1.apply(key));
+        final OutdatableResult<T2> outdatable1 = storage2.getOutdatable(getKey2.apply(key));
+        return new OutdatableResult<>(outdatable.getResult().thenCombine(outdatable1.getResult(), resultMapper.apply(key)),
+                CompletableFuture.anyOf(outdatable.getOutdated(), outdatable1.getOutdated()).thenApply(x -> null));
     }
 }