diff --git a/src/MultiSet.java b/src/MultiSet.java
new file mode 100644
index 0000000..5bb67fe
--- /dev/null
+++ b/src/MultiSet.java
@@ -0,0 +1,49 @@
+import java.util.*;
+
+public interface MultiSet<E> {
+    /**
+     * Adds the specified item to this multiset.
+     *
+     * @param item item to be added
+     * @return true if the item was added successfully, false otherwise
+     */
+    boolean add(E item);
+
+    /**
+     * Removes the specified item from this multiset.
+     *
+     * @param item item to be removed
+     */
+    void remove(E item);
+
+    /**
+     * Returns true if this multiset contains the specified item.
+     *
+     * @param item item whose presence in this multiset is to be tested
+     * @return true if this multiset contains the specified item
+     */
+    boolean contains(E item);
+
+    /**
+     * Returns true if this multiset contains no items.
+     *
+     * @return true if this multiset contains no items
+     */
+    boolean isEmpty();
+
+    /**
+     * Returns the count of the specified item in this multiset.
+     *
+     * @param item item whose count is to be returned
+     * @return the count of the specified item in this multiset
+     */
+    int count(E item);
+
+    /**
+     * Returns the number of items in this multiset.
+     *
+     * @return the number of items in this multiset
+     */
+    int size();
+}
+