import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.NoSuchElementException;

public class Main {

	final long MOD = (long) 1e9 + 7;
	ArrayList<Integer>[] g;
	HashMap<Long, Integer> cols = new HashMap<>();
	int colsz = 0;

	void dfs(int cur, int par, int parcol) {
		int col = 0;
		for (int dst : g[cur]) {
			if (dst == par)
				continue;
			if (col == parcol)
				++col;
			cols.put((long) dst << 32 | cur, col);
			cols.put((long) cur << 32 | dst, col);
			dfs(dst, cur, col);
			++col;
			colsz = Math.max(colsz, col);
		}
	}

	void run() {
		FastScanner sc = new FastScanner();
		int N = sc.nextInt();
		g = new ArrayList[N];
		for (int i = 0; i < N; ++i)
			g[i] = new ArrayList<Integer>();
		int[] a = new int[N - 1];
		int[] b = new int[N - 1];
		for (int i = 0; i < N - 1; ++i) {
			a[i] = sc.nextInt();
			b[i] = sc.nextInt();
			--a[i];
			--b[i];
			g[a[i]].add(b[i]);
			g[b[i]].add(a[i]);
		}
		dfs(0, -1, -1);
		PrintWriter pw = new PrintWriter(System.out);
		pw.println(colsz);
		for (int i = 0; i < N - 1; ++i) {
			pw.println(cols.get((long) a[i] << 32 | b[i]) + 1);
		}
		pw.close();
	}

	public static void main(String[] args) throws FileNotFoundException {
		new Main().run();
	}

	void tr(Object... objects) {
		System.out.println(Arrays.deepToString(objects));
	}
}

class FastScanner {
	private final InputStream in = System.in;
	private final byte[] buffer = new byte[1024];
	private int ptr = 0;
	private int buflen = 0;

	private boolean hasNextByte() {
		if (ptr < buflen) {
			return true;
		} else {
			ptr = 0;
			try {
				buflen = in.read(buffer);
			} catch (IOException e) {
				e.printStackTrace();
			}
			if (buflen <= 0) {
				return false;
			}
		}
		return true;
	}

	private int readByte() {
		if (hasNextByte())
			return buffer[ptr++];
		else
			return -1;
	}

	private static boolean isPrintableChar(int c) {
		return 33 <= c && c <= 126;
	}

	public boolean hasNext() {
		while (hasNextByte() && !isPrintableChar(buffer[ptr]))
			ptr++;
		return hasNextByte();
	}

	public String next() {
		if (!hasNext())
			throw new NoSuchElementException();
		StringBuilder sb = new StringBuilder();
		int b = readByte();
		while (isPrintableChar(b)) {
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}

	public long nextLong() {
		if (!hasNext())
			throw new NoSuchElementException();
		long n = 0;
		boolean minus = false;
		int b = readByte();
		if (b == '-') {
			minus = true;
			b = readByte();
		}
		if (b < '0' || '9' < b) {
			throw new NumberFormatException();
		}
		while (true) {
			if ('0' <= b && b <= '9') {
				n *= 10;
				n += b - '0';
			} else if (b == -1 || !isPrintableChar(b)) {
				return minus ? -n : n;
			} else {
				throw new NumberFormatException();
			}
			b = readByte();
		}
	}

	public int nextInt() {
		long nl = nextLong();
		if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE)
			throw new NumberFormatException();
		return (int) nl;
	}

	public double nextDouble() {
		return Double.parseDouble(next());
	}
}

Measured memory_bytes: 82668