#include "testlib.h"
#include <bits/stdc++.h>
#include <atcoder/dsu>
using namespace std;
using ll = long long;

const int Nmin = 2;
const int Nmax = 200'000;

int main(){
    registerValidation();
	int N = inf.readInt(Nmin, Nmax);
	inf.readEoln();
	atcoder::dsu uf(N);
	for (int i=0; i<N-1; i++){
		int u = inf.readInt(1, N);
		inf.readSpace();
		int v = inf.readInt(1, N);
		inf.readEoln();
		u--; v--;
		uf.merge(u, v);
	}
	inf.readEof();
	assert(uf.size(0) == N);
}