using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace AtCorder
{
	public class Program
	{
		static void Main(string[] args)
		{
			var cin = new Scanner2();
			int n = cin.Int();
			Dictionary<int, int>[] to = new Dictionary<int, int>[n];
			Edge[] edge = new Edge[n - 1];
			for (int i = 0; i < n; i++) {
				to[i] = new Dictionary<int, int>();
			}

			int first = 0;
			for (int i = 0; i < n - 1; i++) {
				int a = cin.Int() - 1;
				int b = cin.Int() - 1;
				to[a].Add(b, -1);
				to[b].Add(a, -1);

				edge[i] = new Edge {
					From = a,
					To = b
				};

				if (i == 0) {
					first = a;
				}
			}

			int num = to.Max(x => x.Count);

			var q = new Queue<ToColor>();
			q.Enqueue(new ToColor { To = first, Color = -1 });
			while (q.Count > 0) {
				var next = q.Dequeue();
				int color = next.Color == -1 ? 0 : (next.Color + 1) % num;
				foreach (var nn in to[next.To].Keys.ToArray()) {
					if (to[next.To][nn] == -1) {
						to[next.To][nn] = color;
						to[nn][next.To] = color;
						q.Enqueue(new ToColor { To = nn, Color = color });
						color = (color + 1) % num;
					}
				}
			}

			var sb = new StringBuilder();
			sb.AppendLine(num.ToString());
			for (int i = 0; i < n - 1; i++) {
				sb.AppendLine((to[edge[i].From][edge[i].To] + 1).ToString());
			}

			Console.WriteLine(sb.ToString());
		}
	}

	public class Edge
	{
		public int From {get; set;}
		public int To { get; set; }
	}

	public class ToColor
	{
		public int To { get; set; }
		public int Color { get; set; }
	}


	public class Scanner2
	{
		private readonly char[] delimiter_ = new char[] { ' ' };
		private readonly string filePath_;
		private string[] buf_;
		private int index_;
		Func<string> reader_;

		public Scanner2(string file = "")
		{
			if (string.IsNullOrWhiteSpace(file)) {
				reader_ = Console.ReadLine;
			} else {
				filePath_ = file;
				var fs = new StreamReader(file);
				reader_ = fs.ReadLine;
			}
			buf_ = new string[0];
			index_ = 0;
		}

		public string Next()
		{
			if (index_ < buf_.Length) {
				return buf_[index_++];
			}

			string st = reader_();
			while (st == "") {
				st = reader_();
			}

			buf_ = st.Split(delimiter_, StringSplitOptions.RemoveEmptyEntries);
			if (buf_.Length == 0) {
				return Next();
			}

			index_ = 0;
			return buf_[index_++];
		}

		public int Int() => int.Parse(Next());
		public long Long() => long.Parse(Next());
		public double Double() => double.Parse(Next());

		public int[] ArrayInt(int N, int add = 0)
		{
			int[] Array = new int[N];
			for (int i = 0; i < N; i++) {
				Array[i] = Int() + add;
			}
			return Array;
		}

		public long[] ArrayLong(int N, long add = 0)
		{
			long[] Array = new long[N];
			for (int i = 0; i < N; i++) {
				Array[i] = Long() + add;
			}
			return Array;
		}

		public double[] ArrayDouble(int N, double add = 0)
		{
			double[] Array = new double[N];
			for (int i = 0; i < N; i++) {
				Array[i] = Double() + add;
			}
			return Array;
		}

		public void Save(string text)
		{
			if (string.IsNullOrWhiteSpace(filePath_)) {
				return;
			}

			File.WriteAllText(filePath_ + "_output.txt", text);
		}
	}
}

Measured memory_bytes: 50216