Write a program for a matchstick game being played between the computer and a user.
your program should ensure that the computer always wins.
rules for the game are as follows:

i-there are 21 matchsticks.

ii-the computer asks the player to pick 1,2,3 or 4 matchsticks.

iii- after the person picks the computer does its picking.

iv- whoever is forced to pick up the last matchstick loses the game.