1 #include <bits/stdc++.h>
 2 using namespace std;
 3 
 4 const int MAXN=1e5+10;
 5 vector<int> v[MAXN];
 6 vector<int> st1, st2;
 7 bool flag=false;
 8 int vis[MAXN];
 9 
10 void dfs(int point){
11     if(flag){
12         return;
13     }
14     for(int i=0; i<v[point].size(); i++){
15         int cnt=v[point][i];
16         if(vis[point]==vis[cnt]){
17             flag=true;
18             return;
19         }else if(!vis[cnt]){
20             if(vis[point]==1){
21                 vis[cnt]=2;
22                 st2.push_back(cnt);
23                 dfs(cnt);
24             }else if(vis[point]==2){
25                 vis[cnt]=1;
26                 st1.push_back(cnt);
27                 dfs(cnt);
28             }
29         }
30     }
31 }
32 
33 int main(void){
34     ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
35     int n, m, x, y;
36     cin >> n >> m;
37     while(m--){
38         cin >> x >> y;
39         v[x].push_back(y);
40         v[y].push_back(x);
41     }
42     for(int i=1; i<=n; i++){
43         if(v[i].size()==0){
44             continue;
45         }else if(!vis[i]){
46             vis[i]=1;
47             st1.push_back(i);
48             dfs(i);
49         }
50     }
51     if(flag){
52         cout << -1 << endl;
53     }else{
54         cout << st1.size() << endl;
55         for(int i=0; i<st1.size(); i++){
56             cout << st1[i] << " ";
57         }
58         cout << endl;
59         cout << st2.size() << endl;
60         for(int i=0; i<st2.size(); i++){
61             cout << st2[i] << " ";
62         }
63         cout << endl;
64     }
65     return 0;
66 }