#include<iostream>
#include<cstdlib>
#include<cstdio>
#include<algorithm>
#define N 3010
#define M 200010
using namespace std;
int n,m,cnt,g[N],DFN,low[M],dfn[M],cut[N],sz[N];
struct nee{int nxt,to;
}e[M];
inline void tarjan(int x,int f){low[x]=dfn[x]=++DFN;sz[x]=0;for(int i=g[x];i;i=e[i].nxt){++sz[x];if(e[i].to==f) continue;if(dfn[e[i].to])    low[u]=min(low[u],dfn[e[i].to]);else{tarjan(e[i].to,x);low[x]=min(low[x],low[e[i].to]);if(x==1){if(sz[x]>=2) cut[x]=1;}else if(low[e[i].to]>dfn[x]) cut[x]=1;}}
}
inline void addedge(int x,int y){e[++cnt].nxt=g[x];g[x]=cnt;e[cnt].to=y;
}
inline void Jimmy(){scanf("%d%d",&n,&m);for(int i=1,u,v;i<=m;i++){scanf("%d%d",&u,&v);addedge(u,v);}tarjan(1,0);for(int i=1;i<=n;i++)    if(cut[i]) printf("%d\n",i);
}
int main(){Jimmy();return 0;
}

#include<iostream>
#include<cstdlib>
#include<cstdio>
#include<algorithm>
#define N 3010
#define M 200010
using namespace std;
int n,m,g[M],cnt,DFN,dfn[M],low[M],cutb;
struct nee{int nxt,to,u,v;
}e[M];
inline addedge(int x,int y){e[++cnt].nxt=g[x];g[x]=cnt;e[cnt].to=y;e[cnt].u=x;e[cnt].v=y;
}
inline void tarjan(int x,int f){low[x]=dfn[x]=++DFN;for(int i=g[x];i;i=e[i].nxt){if(e[i].to==f) continue;if(dfn[e[i].to]) low[x]=min(low[x],dfn[e[i].to]);else {tarjan(e[i].to,x);low[x]=min(low[x],low[e[i].to]);}}
}
inline void Jimmy(){scanf("%d%d",&n,&m);for(int i=1,u,v;i<=m;i++){scanf("%d%d",&u,&v);addedge(u,v);}tarjan(1,0);for(int i=1;i<=m;i++){if(dfn[e[i].u]>dfn[e[i].v]) swap(e[i].u,e[i].v);if(low[e[i].v]>dfn[e[i].u]) ++cutb;}printf("%d\n",cutb);
}
int main(){Jimmy();return 0;
}