#include<bits/stdc++.h>
#define endl "\n"
using namespace std;
vector<int> e[100005];
bool vis[100005];//用于找根节点 
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	int n,m;
	cin>>n>>m;
	for(int i=1;i<=m;i++)
	{
		int x,y;
		cin>>x>>y;
		e[x].push_back(y);
		vis[y]=1; 
	}
	int maxx=1;
	for(int i=1;i<=n;i++)
	{
		sort(&e[i][0],&e[i][e[i].size()]);//对子节点排序 
		if(e[i].size()==e[maxx].size())
			if(i<maxx) maxx=i;//取较小的节点 
		if(e[i].size()>e[maxx].size())
			maxx=i;
	}
	int ans;
	for(int i=1;i<=n;i++)
		if(vis[i]==0)
			ans=i;
	cout<<ans<<endl;
	cout<<maxx<<endl;
	for(int i=0;i<e[maxx].size();i++)
		cout<<e[maxx][i]<<" ";
	return 0;
}