#include<cstdio>

 #include<cmath>

 #include<algorithm>

 #include<cstring>

 #include<iostream>

 int tot,go[],next[],first[],id[];

 int son[],f[],v[],n;

 int read(){

     int t=,f=;char ch=getchar();

     while (ch<''||ch>''){if (ch=='-') f=-;ch=getchar();}

     while (''<=ch&&ch<=''){t=t*+ch-'';ch=getchar();}

     return t*f;

 }

 void insert(int x,int y,int Id){

     tot++;

     go[tot]=y;

     next[tot]=first[x];

     first[x]=tot;

     id[tot]=Id;

 }

 void add(int x,int y){

     insert(x,y,);insert(y,x,-);

 }

 void dfs(int x,int fa){

     son[x]=;

     for (int i=first[x];i;i=next[i]){

         int pur=go[i];

         if (pur==fa) continue;

         if (id[i]==-) v[pur]=;

         dfs(pur,x);

         son[x]+=son[pur]+v[pur];

     }

 }

 void dp(int x,int fa){

     for (int i=first[x];i;i=next[i]){

         int pur=go[i];

         if (pur==fa) continue;

         if (id[i]==) f[pur]=f[x]+;

         else f[pur]=f[x]-;

         dp(pur,x);

     }

 }

 int main(){

     n=read();

     for (int i=;i<n;i++){

         int x=read(),y=read();

         add(x,y);

     }

     dfs(,);

     f[]=son[];

     dp(,);

     int ans=n;

     for (int i=;i<=n;i++) ans=std::min(ans,f[i]);

     printf("%d\n",ans);

     for (int i=;i<=n;i++) if (ans==f[i])

      printf("%d ",i);

     return ;

 }