import java.io.PrintStream;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws Exception{
		new Main(new Scanner(System.in), System.out, System.err).exec();
	}
	public final Scanner sc;
	public final PrintStream out, err;
	public Main(final Scanner sc, final PrintStream out, final PrintStream err) {
		this.sc = sc;this.out = out;this.err = err;
	}
	static public final long pair(int a, int b) {return (((long)a) << 32) + b;}
	static public final int getPair1(long v) {return (int)(v >> 32);}
	static public final int getPair2(long v) {return (int)(v & 0xFFFFFFFF);}

	static public final long quad(long a, long b, long c, long d) {
		return ((a&0xFFFF)<< 48) + ((b&0xFFFF)<< 32) + ((c&0xFFFF)<< 16) +(d&0xFFFF);}
	static public final int getQuad1(long v) {return (int)( v >> 48          );}
	static public final int getQuad2(long v) {return (int)((v >> 32) & 0xFFFF);}
	static public final int getQuad3(long v) {return (int)((v >> 16) & 0xFFFF);}
	static public final int getQuad4(long v) {return (int)( v        & 0xFFFF);}

	static public final long record(int e, int m, int i) {
		return quad(-1, e, m, i);
	}
	static public final int re(long record) {
		return getQuad2(record);
	}
	static public final int rm(long record) {
		return getQuad3(record);
	}
	static public final int ri(long record) {
		return getQuad4(record);
	}

	//------------------------------------------

	private int p;
	private int[] inv;
	private int[] fact;
	private int[] finv;
	public final int mod(long v) {
		v %= p;
		return (int)(v < 0 ? v+p : v);
	}
	public final int mul(long a, long b) {
		return mod(a*b);
	}
	public final void initFact(double limit, double p) {
		initFact((int)limit, (int)p);
	}
	public final void initFact(int limit, int p) {
		this.p = p;
		this.inv = new int[limit+1];
		this.fact = new int[limit+1];
		this.finv = new int[limit+1];
		fact[1] = finv[1] = inv[0] = inv[1] = 1;
		for(int i=2;i<=limit;i++) {
			int a = p / i;
			int b = p % i;
			inv[i]  = mul(-a, inv[b]);
			fact[i] = mul(fact[i-1], i);
			finv[i] = mul(finv[i-1], inv[i]);
		}
	}
	public final int comb(int m, int n) {
		return mul(mul(fact[m], finv[n]), finv[m-n]);
	}

	//------------------------------------------

	static public class Edge{
		private int index;
		private int start;
		private int end;
		private int coler;
	}

	public void exec() throws Exception{
		final int N = sc.nextInt();
		final Edge[] edges = new Edge[N-1];
		final int[] parentColors = new int[N+1];
		for(int i=0;i<N-1;i++) {
			final int a = sc.nextInt();
			final int b = sc.nextInt();
			edges[i]=new Edge();
			edges[i].index=i;
			edges[i].start=a;
			edges[i].end=b;
		}
		Arrays.sort(edges, new Comparator<Edge>() {
			@Override
			public int compare(Edge o1, Edge o2) {
				return Integer.compare(o1.start, o2.start);
			}
		});
		int K = 0;
		int e = 0;
		for(int i=1;i<=N;i++) {
			int color = 1;
			int parentColor = parentColors[i];
			while(e<edges.length && edges[e].start==i) {
				if(parentColor==color) {
					color++;
				}
				edges[e].coler = color;
				parentColors[edges[e].end] = color;
				e++;
				color++;
			}
			K = Math.max(K, color-1);
		}
		Arrays.sort(edges, new Comparator<Edge>() {
			@Override
			public int compare(Edge o1, Edge o2) {
				return Integer.compare(o1.index, o2.index);
			}
		});
		out.println(K);
		for(Edge edge : edges) {
			out.println(edge.coler);
		}
	}
}


Measured memory_bytes: 69640