#abc240e. [abc240_e]Ranges on Tree

[abc240_e]Ranges on Tree

Problem Statement

You are given a rooted tree with NN vertices. The root is Vertex 11.
For each i=1,2,ldots,N1i = 1, 2, \\ldots, N-1, the ii-th edge connects Vertex uiu_i and Vertex viv_i.

For each i=1,2,ldots,Ni = 1, 2, \\ldots, N, let SiS_i denote the set of all vertices in the subtree rooted at Vertex ii. (Each vertex is in the subtree rooted at itself, that is, iinSii \\in S_i.)

Additionally, for integers ll and rr, let \[l, r\] denote the set of all integers between ll and rr, that is, $\[l, r\] = \\lbrace l, l+1, l+2, \\ldots, r \\rbrace$.

Consider a sequence of NN pairs of integers $\\big((L_1, R_1), (L_2, R_2), \\ldots, (L_N, R_N)\\big)$ that satisfies the conditions below.

  • 1leqLileqRi1 \\leq L_i \\leq R_i for every integer ii such that 1leqileqN1 \\leq i \\leq N.
  • The following holds for every pair of integers (i,j)(i, j) such that 1leqi,jleqN1 \\leq i, j \\leq N.
    • \[L_i, R_i\] \\subseteq \[L_j, R_j\] if SisubseteqSjS_i \\subseteq S_j
    • \[L_i, R_i\] \\cap \[L_j, R_j\] = \\emptyset if SicapSj=emptysetS_i \\cap S_j = \\emptyset

It can be shown that there is at least one sequence $\\big((L_1, R_1), (L_2, R_2), \\ldots, (L_N, R_N)\\big)$. Among those sequences, print one that minimizes $\\max \\lbrace L_1, L_2, \\ldots, L_N, R_1, R_2, \\ldots, R_N \\rbrace$, the maximum integer used. (If there are multiple such sequences, you may print any of them.)

Constraints

  • 2leqNleq2times1052 \\leq N \\leq 2 \\times 10^5
  • 1lequi,vileqN1 \\leq u_i, v_i \\leq N
  • All values in input are integers.
  • The given graph is a tree.

Input

Input is given from Standard Input in the following format:

NN u1u_1 v1v_1 u2u_2 v2v_2 vdots\\vdots uN1u_{N-1} vN1v_{N-1}

Output

Print NN lines in the format below. That is, for each i=1,2,ldots,Ni = 1, 2, \\ldots, N, the ii-th line should contain LiL_i and RiR_i separated by a space.

L1L_1 R1R_1 L2L_2 R2R_2 vdots\\vdots LNL_N RNR_N


Sample Input 1

3
2 1
3 1

Sample Output 1

1 2
2 2
1 1

$(L_1, R_1) = (1, 2), (L_2, R_2) = (2, 2), (L_3, R_3) = (1, 1)$ satisfies the conditions.
Indeed, we have $\[L_2, R_2\] \\subseteq \[L_1, R_1\], \[L_3, R_3\] \\subseteq \[L_1, R_1\], \[L_2, R_2\] \\cap \[L_3, R_3\] = \\emptyset$.
Additionally, $\\max \\lbrace L_1, L_2, L_3, R_1, R_2, R_3 \\rbrace = 2$ is the minimum possible value.


Sample Input 2

5
3 4
5 4
1 2
1 4

Sample Output 2

1 3
3 3
2 2
1 2
1 1

Sample Input 3

5
4 5
3 2
5 2
3 1

Sample Output 3

1 1
1 1
1 1
1 1
1 1