#!/usr/bin/env python3
import sys
sys.setrecursionlimit(10**9)
input = sys.stdin.readline

n = int(input())
edge = [[] for _ in [0]*n]
for i in range(~-n):
    a, b = map(int, input().split())
    a -= 1;b -= 1
    edge[a] += [[b, i]]
ans = [0] * ~-n

def dfs(now, color):
    count = 1
    for to, i in edge[now]:
        # 親の色と同じとき
        if count == color:
            count += 1
        ans[i] = count
        dfs(to, count)
        count += 1

# 開始根は0番目に
dfs(0, 0)

print(max(ans))
for p in ans:
    print(p)
