#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
int tree[105],n,m,x,y;
int par[105];
int root,maxn;
int main()
{
	memset(tree,-1,sizeof(tree));
	//fill(tree,tree+105,-1);
    cin>>n>>m;
	while(m--){
		cin>>x>>y;
		tree[y]=x;
		par[x]++;
		if(par[maxn]<par[x]) maxn=x;
		if(tree[x]==-1){
			tree[x]=0;
			root=x;
		}
	}
	cout<<root<<"\n"<<maxn<<endl;
	for(int i=1;i<=n;i++) 
		if(tree[i]==maxn) cout<<i<<" ";
    return 0;
}