diff --git a/w8/Pair.java b/w8/Pair.java
new file mode 100644
index 0000000..15e5a64
--- /dev/null
+++ b/w8/Pair.java
@@ -0,0 +1,21 @@
+public class Pair<K,V>{
+    public K key;
+    public V value;
+    public Pair(K key,V value){
+        this.key=key;
+        this.value=value;
+    }
+    public static <K,V> Pair<V,K> swap(Pair<K,V> pair){
+        return new Pair<>(pair.value, pair.key);
+    }
+    @Override
+    public String toString() {
+        return "(" + key + ", " + value + ")";
+    }
+    public static void main(String[] args) {
+        Pair<String, Integer> p1 = new Pair<>("age", 20);
+        System.out.println("before" + p1);
+        Pair<Integer, String> p2 = Pair.swap(p1);
+        System.out.println("now" + p2);
+    }
+}
\ No newline at end of file