Moving Coins Game

[Dr. Atul Nischal]

Arnab and Bina are playing the "Moving Coins" game. They alternate turns removing coins from three piles. At the beginning of the game:

1. the first pile contains 1 coin, 
2. the second pile contains 2 coins and
3. the third pile contains 3 coins. 

Players can remove:

• coins from any one pile.
• as many coins as they want. 

The player who removes the last coin wins the game.

Arnab starts the game. Bina claims that no matter what Arnab does on his turn, she can win by following her strategy.

Can you describe Bina's winning strategy?