CF1325C.Ehab and Path-etic MEXs

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题目描述

You are given a tree consisting of nn nodes. You want to write some labels on the tree's edges such that the following conditions hold:

  • Every label is an integer between 00 and n2n-2 inclusive.
  • All the written labels are distinct.
  • The largest value among MEX(u,v)MEX(u,v) over all pairs of nodes (u,v)(u,v) is as small as possible.

Here, MEX(u,v)MEX(u,v) denotes the smallest non-negative integer that isn't written on any edge on the unique simple path from node uu to node vv .

输入格式

The first line contains the integer nn ( 2n1052 \le n \le 10^5 ) — the number of nodes in the tree.

Each of the next n1n-1 lines contains two space-separated integers uu and vv ( 1u,vn1 \le u,v \le n ) that mean there's an edge between nodes uu and vv . It's guaranteed that the given graph is a tree.

输出格式

Output n1n-1 integers. The ithi^{th} of them will be the number written on the ithi^{th} edge (in the input order).

输入输出样例

  • 输入#1

    3
    1 2
    1 3

    输出#1

    0
    1
  • 输入#2

    6
    1 2
    1 3
    2 4
    2 5
    5 6

    输出#2

    0
    3
    2
    4
    1

说明/提示

The tree from the second sample:

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