what will be the output of thread problem?

Problem statement:
what will be the output of the following code?

1. public class Person extends Thread {
2.     private int count;
3.     private Person(int count) {
4.         this.count = count;
5.     }
6.     @Override
7.     public void run() {
8.         for (int i = 1; i < 4; i++) {
9.             count = count + 1;
10.         }
11.     }
12.     public static void main(String[] args) {
13.         Person t = new Person(10);
14.         t.start();
15.         System.out.println(t.count);
16.     }
17. }

Output: 10

output will vary, will explain the reason soon