Daisy Chains in the Field
题号:NC24742
时间限制:C/C++/Rust/Pascal 1秒,其他语言2秒
空间限制:C/C++/Rust/Pascal 32 M,其他语言64 M
64bit IO Format: %lld

题目描述

Farmer John let his N (1 <= N <= 250) cows conveniently numbered 1..N play in the field. The cows decided to connect with each other using cow-ropes, creating M (1 <= M <= N*(N-1)/2) pairwise connections. Of course, no two cows had more than one rope directly connecting them. The input shows pairs of cows c1 and c2 that are connected (1 <= c1 <= N; 1 <= c2 <= N; c1 != c2).
FJ instructed the cows to be part of a chain which contained cow #1. Help FJ find any misbehaving cows by determining, in ascending order, the numbers of the cows not connected by one or more ropes to cow 1 (cow 1 is always connected to herself, of course). If there are no misbehaving cows, output 0.
To show how this works, consider six cows with four connections:
    1---2  4---5
     \  |
      \ |      6
       \|
        3
Visually, we can see that cows 4, 5, and 6 are not connected to cow 1.

输入描述:

* Line 1: Two space-separated integers: N and M
* Lines 2..M+1: Line i+1 shows two cows connected by rope i with two space-separated integers: c1 and c2

输出描述:

* Lines 1..???: Each line contains a single integer
示例1

输入

复制
6 4
1 3
2 3
1 2
4 5

输出

复制
4
5
6