java.lang.ClassCastException: java.lang.String while iterating Priority Queue

ADDITIONAL SYSTEM INFORMATION :
package stlabs.collectionframework;

import java.util.Iterator;
import java.util.LinkedList;
import java.util.PriorityQueue;
import java.util.Queue;

public class QueueProgram
{
    public static void main(String[] args)
    {
        Queue<Object> queue=new PriorityQueue<>();
        queue.add("Ankit");
        queue.add("Sandip");
        queue.add("Pankaj");
        queue.add(10);
        queue.remove("Sandip");

        Iterator itr= queue.iterator();
        while(itr.hasNext())
        {
            System.out.println(itr.next());
        }
    }
}


A DESCRIPTION OF THE PROBLEM :
Exception in thread "main" java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Integer
at java.lang.Integer.compareTo(Integer.java:52)
at java.util.PriorityQueue.siftUpComparable(PriorityQueue.java:657)
at java.util.PriorityQueue.siftUp(PriorityQueue.java:648)
at java.util.PriorityQueue.offer(PriorityQueue.java:345)
at java.util.PriorityQueue.add(PriorityQueue.java:322)
at stlabs.collectionframework.QueueProgram.main(QueueProgram.java:16)