Tree Operations (Easy)

**This is the easy version of the problem. The only difference is that here, $Q = 1$. This version is worth $100$ points in all Divisions.** You are given a tree with $N$ nodes, rooted at $1$. Each node $i$ has an associated non-negative integer value $A_i$. The **score of a tree** is defined as the minimum number of times you need to apply the following operation to reduce all $A_i$ to $0$: -