#include<bits/stdc++.h>
using namespace std;
bool flag, vis[100];
vector<int> a[100];
void dfs(int n, int target) {
vis[n] = 1;
if (n == target) {
flag = true;
return;
}
for (int i = 0; i < a[n].size(); i++) {
int next = a[n][i];
if (!vis[next]) {
dfs(next, target);
if (flag) return;
}
}
}
int main() {
int n; cin >> n;
for (int i = 1; i < n; i++) {
int x, y;
cin >> x >> y;
a[x-1].push_back(y-1); // 统一存储为 0-based
}
}
