#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
const long long int mod = 1000000007;
const long long int inf = 0x3f3f3f3f3f3f3f3fLL;
const double eps = 1e-9;
const double PI = acos(-1);
long long int i, j, k;
void solve(void);
inline bool equal(double a, double b) { return fabs(a - b) < eps; }
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout << fixed << setprecision(10);
  int t = 1;
  while (t--) solve();
  ;
  ;
  return 0;
}
vector<long long int> node[500005];
bool vis[500005], blocked[1000005];
pair<long long int, long long int> ans[500005];
long long int maxr;
void dfs(int idx, int l) {
  vis[idx] = 1;
  int child = (int)node[idx].size() - 1;
  if (idx == 1) ++child;
  ans[idx].first = l;
  blocked[l] = 1;
  i = maxr + child;
  ans[idx].second = i;
  blocked[i] = 1;
  maxr = ((maxr) > (i + 1) ? (maxr) : (i + 1));
  long long int r = ans[idx].second - 1;
  for (auto it : node[idx])
    if (!vis[it]) {
      dfs(it, r);
      --r;
    }
}
void solve() {
  int n;
  cin >> n;
  for (i = 1; i <= n - 1; ++i) {
    int x, y;
    cin >> x >> y;
    node[x].emplace_back(y);
    node[y].emplace_back(x);
  }
  maxr = 2;
  dfs(1, 1);
  for (i = 1; i <= n; ++i) cout << ans[i].first << ' ' << ans[i].second << '\n';
}
