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;
const int MAXN = (int)5e5;
int n, st[MAXN + 5], fn[MAXN + 5], cur = 1;
vector<int> ms[MAXN + 5];
void dfs(int first, int p) {
  cur += (int)ms[first].size();
  int sad = cur;
  fn[first] = sad--;
  for (vector<int>::iterator i = ms[first].begin(); i != ms[first].end(); ++i) {
    int o = *i;
    if (o == p) continue;
    st[o] = sad--;
    dfs(o, first);
  }
}
int main() {
  scanf("%d", &n);
  for (int i = 0; i < n - 1; ++i) {
    int first, second;
    scanf("%d %d", &first, &second);
    ms[first].push_back(second);
    ms[second].push_back(first);
  }
  st[1] = cur++;
  dfs(1, -1);
  for (int i = 1; i <= n; ++i) {
    printf("%d %d\n", st[i], fn[i]);
  }
  return 0;
}