Problem: We had a really tough time generating tests for problem D. In order to prepare strong tests, we had to solve the following problem.

Given an undirected labeled tree consisting of n vertices, find a set of segments such that:

  1. both endpoints of each segment are integers from 1 to 2n, and each integer from 1 to 2n should appear as an endpoint of exactly one segment; 
  2. all segments are non-degenerate; 
  3. for each pair (i, j) such that i ≠ j, i ∈ [1, n] and j ∈ [1, n], the vertices i and j are connected with an edge if and only if the segments i and j intersect, but neither segment i is fully contained in segment j, nor segment j is fully contained in segment i. 



Can you solve this problem too?

Input

The first line contains one integer n (1 ≤ n ≤ 5 ⋅ 10^5) — the number of vertices in the tree.

Then n - 1 lines follow, each containing two integers x_i and y_i (1 ≤ x_i, y_i ≤ n, x_i ≠ y_i) denoting the endpoints of the i-th edge.

It is guaranteed that the given graph is a tree.

Output

Print n pairs of integers, the i-th pair should contain two integers l_i and r_i (1 ≤ l_i < r_i ≤ 2n) — the endpoints of the i-th segment. All 2n integers you print should be unique.

It is guaranteed that the answer always exists.

Examples

Input


6
1 2
1 3
3 4
3 5
2 6


Output


9 12
7 10
3 11
1 5
2 4
6 8


Input


1


Output


1 2

Solution (in CPP):

Solution:
#include <bits/stdc++.h>
using namespace std;
mt19937 rnd(time(0));
const int32_t SMALL = LONG_MIN >> 1;
const int32_t BIG = LONG_MAX >> 1;
const int32_t MAXN = 500001;
int32_t st[MAXN], en[MAXN];
vector<int32_t> g[MAXN];
int32_t n, cur;
void dfs(int32_t u, int32_t p) {
  for (int32_t v : g[u])
    if (v != p) st[v] = ++cur;
  en[u] = ++cur;
  reverse(g[u].begin(), g[u].end());
  for (int32_t v : g[u])
    if (v != p) dfs(v, u);
  return;
}
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> n;
  for (int32_t i = 1; i < n; i++) {
    int32_t u, v;
    cin >> u >> v;
    g[u].push_back(v);
    g[v].push_back(u);
  }
  st[1] = ++cur;
  dfs(1, -1);
  for (int32_t i = 1; i <= n; i++) cout << st[i] << " " << en[i] << endl;
}