Challenge #1: 21

Question

Make a game that allows the user to play a game of 21 with the computer.
21 is a game in which you count up to 21 with a player. The player that says 21 loses.
Each player can count up to a maximum of 3 each turn.
E.g Player 1 starts off with 1, player 2 can say 2,3 or 4.
Or player 1 starts off with 3, player 2 can say a number from 4 to 7.

So the conditions are as follows:
Game supports 1 player to play against the computer.
Each has one turn at a time.
They must pick a number.
They can only count up by 1, 2 or 3 each turn.
When a player is forced to count up to 21, they lose.
The game must specify who wins and who loses.

Begin!!!

Answer 1

Code the game mate

Answer 2

1