diff --git a/pom.xml b/pom.xml
index a9f439170d47e95202697423f3d2cc1dce649e8b..f81f4249ee39a7b829b333b750e79b16fab42777 100644
--- a/pom.xml
+++ b/pom.xml
@@ -62,6 +62,10 @@
             <artifactId>jgraphx</artifactId>
             <version>1.10.1.3</version>
         </dependency>
-
+        <dependency>
+            <groupId>it.unimi.dsi</groupId>
+            <artifactId>fastutil</artifactId>
+            <version>7.0.12</version>
+        </dependency>
     </dependencies>
 </project>
\ No newline at end of file
diff --git a/src/main/java/fucoin/wallet/WalletImpl.java b/src/main/java/fucoin/wallet/WalletImpl.java
index 6f668e5ca3b84e3f92a1dca369cecb208061e749..88e64c9eb7c9242632a59ae0e957d01866be02d4 100644
--- a/src/main/java/fucoin/wallet/WalletImpl.java
+++ b/src/main/java/fucoin/wallet/WalletImpl.java
@@ -21,6 +21,9 @@ import java.util.concurrent.ConcurrentLinkedQueue;
 
 public class WalletImpl extends AbstractWallet {
 
+    private static final double sCompression = 0.7;
+    private QDigest qDigest = new QDigest(sCompression);
+
     private ActorRef preKnownNeighbour;
     private ActorRef remoteSuperVisorActor;
     private transient WalletGuiControl gui;
@@ -51,6 +54,7 @@ public class WalletImpl extends AbstractWallet {
      */
     public void addAmount(int amount) {
         setAmount(this.getAmount() + amount);
+        qDigest.offer(amount);
         addLogMsg(" My amount is now " + this.getAmount());
     }