Chris and Dylan are playing a game. Here are the rules：  1. There are $$7$$ matches placed in a row.  2. The players take turns removing either $1$ or $2$ matches each turn.  3. Whoever picks the last match wins the game.  Chris starts first and is followed by Dylan. To ensure his victory, how many matches must Chris take away in the first turn? 
Overseas Competition->Knowledge Point->Combinatorics->Strategies and Operations->Game Strategy