$6.$ Write a program that allows the user to input a succession of integers until the same integer is entered three times in a row. At this point, the program should stop and print Threepeat!

So$,$ a sample run of the program might look like:

Number? $5$

Number? $19$

Number? $5$

Number? $5$

Number? $7$

Number? $7$

Number? $7$

Threepeat!

$($where all the numbers are user input, and everything else is printed by the program$).$