释放无限光明的是人心，制造无边黑暗的也是人心，光明和黑暗交织着，厮杀着，这就是我们为之眷恋又万般无奈的人世间。

A graph which is connected and acyclic can be considered a tree. The height of the tree depends on the selected root. Now you are supposed to find the root that results in a highest tree. Such a root is called the deepest root.

Input Specification:

Each input file contains one test case. For each case, the first line contains a positive integer N (≤104) which is the number of nodes, and hence the nodes are numbered from 1 to N. Then N−1 lines follow, each describes an edge by given the two adjacent nodes' numbers.

Output Specification:

For each test case, print each of the deepest roots in a line. If such a root is not unique, print them in increasing order of their numbers. In case that the given graph is not a tree, print Error: K components where K is the number of connected components in the graph.

Sample Input 1:

Sample Output 1:

3
4
5

Sample Input 2:

Sample Output 2:

Error: 2 components

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <string>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <vector>
#include <ctime>
#include <cctype>
#include <bitset>
#include <utility>
#include <sstream>
#include <complex>
#include <iomanip>
#include<climits>//INT_MAX
//#include<bits/stdc++.h>
#define PP pair<ll,int>
#define inf 0x3f3f3f3f
#define llinf 0x3f3f3f3f3f3f3f3fll
#define dinf 1000000000000.0
#define PI 3.1415926
typedef long long ll;
using namespace std;
int const mod=1e9+7;
const int maxn=2e3+10;
vector<vector<int>> mp;
bool vis[10010];
int mxh=1;
vector<int> tmp;
set<int> s;
void dfs(int node, int height) {if (height>mxh){tmp.clear();tmp.push_back(node);mxh=height;}else if (height==mxh)tmp.push_back(node);vis[node]=true;for (int i=0; i<mp[node].size(); i++){if(vis[mp[node][i]]==false)dfs(mp[node][i], height+1);}
}
int main() {int n,a,b;scanf("%d", &n);mp.resize(n + 1);for (int i=1; i<n; i++) {scanf("%d %d", &a, &b);mp[a].push_back(b);mp[b].push_back(a);}int ct=0,s1;for (int i=1; i<=n; i++) {if (vis[i]==false) {dfs(i, 1);if (i==1) {if(tmp.size()!=0)s1=tmp[0];for (int j=0; j<tmp.size(); j++)s.insert(tmp[j]);}ct++;}}if (ct>=2)printf("Error: %d components\n", ct);else {tmp.clear();fill(vis, vis+10010, false);dfs(s1, 1);for (int i=0; i<tmp.size(); i++)s.insert(tmp[i]);for (set<int>::iterator it=s.begin(); it!=s.end(); it++)printf("%d\n", *it);}return 0;
}

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