Positive Prefixes

You are given two positive integers $N$ and $K$, where $K \le N$. Find a sequence $A_1, A_2, \ldots, A_N$ such that: - for each valid $i$, $A_i$ is either $i$ or $-i$ - there are exactly $K$ values of $i$ such that $1 \le i \le N$ and $A_1 + A_2 + \ldots + A_i \gt 0$ If there are multiple solutions, you may print any one of them. It can be proved that at least one solution always exists. #