MultiThreading in python

from threading import *
from time import sleep

class Hello(Thread):
    def run(selfs):
        for i in range(5):
            print("hello")
            sleep(1)


class Hi(Thread):
    def run(selfs):
        for i in range(5):
            print("hi")
            sleep(1)

t1 = Hello()
t2 = Hi()

t1.start()
sleep(0.2)
t2.start()

hello
hi
hello
hi
hello
hi
hello
hi
hello
hi