Farmer John has $N$ cows, conveniently numbered $1 \dots N$. Every day each cow walks from the barn to her own private pasture.
The pastures form a tree of $N$ nodes; the barn sits at pasture $1$. Exactly $N-1$ two-way paths connect the pastures, and any two directly connected pastures share exactly one path, so there is a unique route between any pair of pastures. Path $i$ connects pastures $A_i$ and $B_i$.
Cow $i$ owns the private pasture $P_i$. Every pasture is owned by exactly one cow, so $P_1, P_2, \dots, P_N$ is a permutation of $1 \dots N$.
The barn's narrow door lets only one cow leave at a time, and each cow waits until the cow before her has reached her own pasture. First cow $1$ leaves and walks from pasture $1$ to $P_1$ and starts eating there. Then cow $2$ leaves and walks from pasture $1$ to $P_2$, and so on.
While cow $i$ walks to $P_i$, she may pass through pastures already occupied by a cow that arrived earlier. Each time she enters such an occupied pasture she slows down to avoid disturbing her friend. In other words, cow $i$ slows down once for every earlier cow (among cows $1 \dots i-1$) whose pasture lies on the route from the barn (pasture $1$) to $P_i$.
In the network below, the number in parentheses is the owner of each pasture:
1 (3)
/ \
(1) 4 3 (5)
/ \
(2) 2 5 (4)
Cow $1$ walks to pasture $4$ and meets no one. Cow $2$ walks to pasture $2$, passing the occupied pasture $4$ on the way, so she slows down once. Cow $3$ owns pasture $1$ (the barn) and slows down zero times. Cow $4$ walks to pasture $5$, passing the occupied pastures $1$ and $4$, slowing down twice. Cow $5$ walks to pasture $3$, passing the occupied pasture $1$, slowing down once.
Farmer John wants to know how many times each cow slows down.