#include <bits/stdc++.h>
using namespace std;
const int mod = 1000000007;
int n;
vector<int> G[500010];
pair<int, int> ans[500010];
int dg[500010];
int Dfs(int ed, int p, int pre) {
  int new_ed = ed;
  int num = 0;
  for (int i = 0; i <= ((int)(G[p]).size()) - 1; ++i) {
    int v = G[p][i];
    if (v == pre) continue;
    num++;
    ans[v] = make_pair(new_ed - num, ed + dg[v]);
    ed = Dfs(ed + dg[v], v, p);
  }
  return ed;
}
int main() {
  scanf("%d", &n);
  for (int i = 1; i <= n - 1; ++i) {
    int a, b;
    scanf("%d %d", &a, &b);
    dg[a]++;
    dg[b]++;
    G[a].push_back(b);
    G[b].push_back(a);
  }
  ans[1] = make_pair(1, dg[1] + 2);
  Dfs(dg[1] + 2, 1, -1);
  for (int i = 1; i <= n; ++i) {
    printf("%d %d\n", ans[i].first, ans[i].second);
  }
  return 0;
}
