#include<cstdio>
#include<iostream>
using namespace std;
#define maxn 20
int vis[maxn];
int g[maxn][maxn];
int g2[maxn][maxn];
int n;
void DFS(int u,int depth)
{
vis[u] = 1;
for(int i = 0;i < n;i++)
{
if(vis[i] == 0 && g2[u][i] == 1)
{
DFS(i,depth + 1);
}
}
}
void clearr()
{
for(int i = 0;i < maxn;i++)
vis[i] = 0;
}
void setg2(int m)
{
for(int i = 0;i < n;i++)
for(int j = 0;j < n;j++)
{
g2[i][j] = g[i][j];
}
for(int i = 0;i < n;i++)
{
g2[m][i] = 0;
g2[i][m] = 0;
}
}
int check(int m)
{
for(int i = 0;i < n;i++)
{
if(vis[i] == 0 && m != i) return 1;
}
return 0;
}
int main()
{
for(int i = 0;i < n;i++)
for(int j = 0;j < n;j++)
{
g[i][j] =0;
}
FILE *fp;
fp = fopen("input4.txt","r+");
fscanf(fp,"%d",&n);
int j,k;
for(int i = 0;i < n;++i)
{
fscanf(fp,"%d",&j);
j--;
if(fscanf(fp,"%d",&k) == EOF) break;
k--;
g[j][k] = 1;
g[k][j] = 1;
}
int flag = 0;
for(int i = 0;i < n;i++)
{
setg2(i);
clearr();
if(i != 0) DFS(0,1);
if(i == 0) DFS(1,1);
if(check(i))
{
printf("%d\n",i+1);
flag = 1;
}
}
if(!(flag)) printf("no such node!");
return 0;
}
//time 126minutes