added ex F

src/exercicses/ex_f/Customer.java

@@ -0,0 +1,26 @@
+package exercicses.ex_f;
+
+public class Customer implements Runnable {
+    private String name;
+    private Account account;
+
+    public Customer(String name, Account account) {
+        this.name = name;
+        this.account = account;
+    }
+
+    @Override
+    public void run() {
+        while (true) {
+            account.deposit((int) (Math.random() * 1000));
+            System.out.println(name + " has deposited money on account with new balance " + account.getBalance());
+            account.withdraw((int) (Math.random() * 1000));
+            System.out.println(name + " has withdrawn money from the account with new balance " + account.getBalance());
+            try {
+                Thread.sleep(100);
+            } catch (InterruptedException e) {
+                throw new RuntimeException(e);
+            }
+        }
+    }
+}