#include <bits/stdc++.h>
using namespace std;
using ll = long long;
template <typename T = int>
struct Compress {
  map<T, int> id;
  vector<T> num;
  Compress(vector<T> v) {
    sort(v.begin(), v.end());
    v.erase(unique(v.begin(), v.end()), v.end());
    num = v;
    for (int i = 0; i < (int)num.size(); i++) {
      id[num[i]] = i;
    }
  }
  inline int get_id(T x) {
    assert(id.count(x));
    return id[x];
  }
  inline T get_num(int i) {
    assert(0 <= i && i < num.size());
    return num[i];
  }
};
void solve() {
  int n;
  cin >> n;
  vector<vector<int>> g(n);
  for (int _ = 1; _ < n; _++) {
    int x, y;
    cin >> x >> y;
    x--;
    y--;
    g[x].emplace_back(y);
    g[y].emplace_back(x);
  }
  vector<pair<ll, ll>> a(n);
  ll D = 1e7;
  ll l = 0;
  function<void(int, int)> dfs = [&](int u, int p) {
    int i = 1;
    for (int v : g[u])
      if (v != p) {
        a[v] = {l -= D, a[u].first + (i++)};
        dfs(v, u);
      }
  };
  a[0] = {l, D};
  dfs(0, -1);
  vector<ll> b;
  for (int i = 0; i < n; i++) {
    b.push_back(a[i].first);
    b.push_back(a[i].second);
  }
  Compress<ll> c(b);
  for (int i = 0; i < n; i++) {
    int x = c.get_id(a[i].first) + 1;
    int y = c.get_id(a[i].second) + 1;
    cout << x << ' ' << y << "\n";
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  solve();
  cout << endl;
}
