2025 SSMO Relay Round 4 Problems/Problem 2

Problem

Let $T = TNYWR.$ Jonathan and Kate are playing a game with $n$ sticks. On each turn, a player may remove $1,$ $2,$ or $3$ sticks. The player who picks up the last stick loses. Kate is first to remove sticks, and both players play optimally. For how many values of $n$ in the range $\left[T^3,2T^3\right]$ does Kate have a winning strategy?

Solution