// Author: Klay Thompson
// Problem: A. All-Star
// Memory Limit: 1024 MB
// Time Limit: 1000 ms
// 
// Powered by CP Editor (https://cpeditor.org)

#include <bits/stdc++.h>

#define rep(i, j, k) for (int i = (j); i <= (k); ++i)
#define per(i, j, k) for (int i = (j); i >= (k); --i)
#define SZ(v) int((v).size())
#define ALL(v) (v).begin(),(v).end()
#define fi first
#define se second
using ll = long long;
using pii = std::pair<int, int>;
using pll = std::pair<ll, ll>;

template<class T>inline void chkmn(T &x, T y) { if (y < x) x = y; }
template<class T>inline void chkmx(T &x, T y) { if (y > x) x = y; }

using namespace std;

const int maxn = 1010;

int n, deg[maxn];
set<int> s[maxn];
vector<tuple<int, int, int>> ans;

int main() {
  cin.tie(nullptr) -> ios::sync_with_stdio(false);
  cin >> n;
  rep (i, 1, n - 1) {
    int u, v;
    cin >> u >> v;
    s[u].insert(v), s[v].insert(u);
    deg[u]++, deg[v]++;
  }
  int rt = 1;
  rep (i, 1, n) if (deg[i] > deg[rt]) rt = i;
  while (true) {
    int x = -1, y = -1;
    for (int p : s[rt]) for (int q : s[p]) if (q != rt) x = p, y = q;
    if (x == -1) break;
    ans.emplace_back(rt, x, y);
    s[x].erase(y), s[y].erase(x), s[rt].insert(y), s[y].insert(rt);
  }
  cout << SZ(ans) << '\n';
  for (auto [a, b, c] : ans) cout << a << " " << b << " " << c << '\n';
}