#include
     
      using namespace std;#define N 10001int n;int v[N<<1],first[N],next[N<<1],en;void AddEdge(int U,int V){    v[++en]=V;    next[en]=first[U];    first[U]=en;}int size[N],fa[N];void dfs(int U){    size[U]=1;    for(int i=first[U];i;i=next[i])      if(v[i]!=fa[U])        {          fa[v[i]]=U;          dfs(v[i]);          size[U]+=size[v[i]];        }}bool check(int U){    if(fa[U]&&n-size[U]>(n>>1))      return 0;    for(int i=first[U];i;i=next[i])      if(v[i]!=fa[U]&&size[v[i]]>(n>>1))        return 0;    return 1;}int main(){    int x,y;    scanf("%d",&n);    for(int i=1;i