import sys
import math
import copy
import heapq
from functools import cmp_to_key
from bisect import bisect_left, bisect_right
from collections import defaultdict, deque, Counter
sys.setrecursionlimit(1000000)

# input aliases
input = sys.stdin.readline
getS = lambda: input().strip()
getN = lambda: int(input())
getList = lambda: list(map(int, input().split()))
getZList = lambda: [int(x) - 1 for x in input().split()]

INF = float("inf")
MOD = 10**9 + 7
divide = lambda x: pow(x, MOD-2, MOD)

def nck(n, k, kaijyo):
    return (npk(n, k, kaijyo) * divide(kaijyo[k])) % MOD

def npk(n, k, kaijyo):
    if k == 0 or k == n:
        return n % MOD
    return (kaijyo[n] * divide(kaijyo[n-k])) % MOD

def fact_and_inv(SIZE):
    inv = [0] * SIZE  # inv[j] = j^{-1} mod MOD
    fac = [0] * SIZE  # fac[j] = j! mod MOD
    finv = [0] * SIZE  # finv[j] = (j!)^{-1} mod MOD
    inv[1] = 1
    fac[0] = fac[1] = 1
    finv[0] = finv[1] = 1
    for i in range(2, SIZE):
        inv[i] = MOD - (MOD // i) * inv[MOD % i] % MOD
        fac[i] = fac[i - 1] * i % MOD
        finv[i] = finv[i - 1] * inv[i] % MOD

    return fac, finv

def renritsu(A, Y):
    # example 2x + y = 3, x + 3y = 4
    # A = [[2,1], [1,3]])
    # Y = [[3],[4]] または [3,4]
    A = np.matrix(A)
    Y = np.matrix(Y)
    Y = np.reshape(Y, (-1, 1))
    X = np.linalg.solve(A, Y)

    # [1.0, 1.0]
    return X.flatten().tolist()[0]

class TwoDimGrid:
    # 2次元座標 -> 1次元
    def __init__(self, h, w, wall="#"):
        self.h = h
        self.w = w
        self.size = (h+2) * (w+2)
        self.wall = wall
        self.get_grid()
        # self.init_cost()

    def get_grid(self):
        grid = [self.wall * (self.w + 2)]
        for i in range(self.h):
            grid.append(self.wall + getS() + self.wall)

        grid.append(self.wall * (self.w + 2))
        self.grid = grid
    def init_cost(self):
        self.cost = [INF] * self.size

    def pos(self, x, y):
        # 壁も含めて0-indexed 元々の座標だけ考えると1-indexed
        return y * (self.w + 2) + x
    def getgrid(self, x, y):
        return self.grid[y][x]
    def get(self, x, y):
        return self.cost[self.pos(x, y)]
    def set(self, x, y, v):
        self.cost[self.pos(x, y)] = v
        return
    def show(self):
        for i in range(self.h+2):
            print(self.cost[(self.w + 2) * i:(self.w + 2) * (i+1)])
    def showsome(self, tgt):
        for t in tgt:
            print(t)
        return
    def showsomejoin(self, tgt):
        for t in tgt:
            print("".join(t))
        return

    def search(self):
        grid = self.grid
        move = [(0, 1), (0, -1), (1, 0), (-1, 0)]
        move_eight = [(0, 1), (0, -1), (1, 0), (-1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
        # for i in range(1, self.h+1):
        #     for j in range(1, self.w+1):
        #         cx, cy = j, i
        #         for dx, dy in move_eight:
        #             nx, ny = dx + cx, dy + cy


def soinsu(n):
    ret = defaultdict(int)
    for i in range(2, int(math.sqrt(n) + 2)):
        if n % i == 0:
            while True:
                if n % i == 0:
                    ret[i] += 1
                    n //= i
                else:
                    break

    if not ret:
        return {n: 1}
    return ret


def solve():
    n = getN()
    graph = [[] for i in range(n)]
    ji = [0 for i in range(n)]
    hen = [0 for i in range(n-1)]
    used = [dict() for i in range(n)]
    for i in range(n - 1):
        a, b = getZList()
        graph[a].append([b, i])
        graph[b].append([a, i])
        ji[a] += 1
        ji[b] += 1
    mji = max(ji)
    mid = ji.index(mji)
    # print(mid)
    d = deque()
    d.append(mid)
    while(d):
        # print(d, hen)
        # print(used)
        cur = d.pop()
        iro = 1
        for nc, np in graph[cur]:
            if hen[np] != 0:
                continue
            # print(iro)
            while True:
                if iro not in used[cur]:
                    hen[np] = iro
                    d.append(nc)
                    used[nc][iro] = 1
                    iro += 1
                    break
                iro += 1


    # jiq = [(ji[i], i) for i in range(n)]
    # jiq.sort(reverse=True)
    # for _, id in jiq:
    #     iro = 0
    #     for tg, he in graph[id]:
    #         # for iro in range(mji):
    #         if hen[he] != 0:
    #             continue
    #         while True:
    #             if iro not in used[id]:
    #                 hen[he] = iro+1
    #                 used[tg][iro] = 1
    #                 iro += 1
    #                 break
    #             iro += 1

    print(mji)
    print(*hen, sep="\n")



def main():
    n = getN()
    for _ in range(n):
        solve()

    return
if __name__ == "__main__":
    # main()
    solve()

Measured memory_bytes: 136092