#include <iostream>
#include <map>
using namespace std;

int main()
{
    int a[105]={};
	int n,m,x,y;
	map<int,int> mp;
	cin>>n>>m;
	while(m--){
		cin>>x>>y;
		if(mp[x]) mp[x]++;
		else mp[x]=1;
		a[y]=x;
	}
	int root=1;
	while(a[root]!=0) root=a[root];
	int maxt=0,maxr=0;
	for(int i=1;i<=n;i++){
		if(maxt<mp[i]){
			maxt=mp[i];
			maxr=i;
		}
	}
	cout<<root<<endl<<maxr<<endl;
	for(int i=1;i<=n;i++){
		if(a[i]==maxr) cout<<i<<" ";
	}
    return 0;
}