import java.io.*;
import java.util.*;

public class Main {
    public static void main(String[] args) throws java.lang.Exception {
        InputReader in = new InputReader(System.in);
        PrintWriter w = new PrintWriter(System.out);
        int n = in.nextInt();
        ArrayList<Integer>[] graph = new ArrayList[n];

        for (int i = 0; i < n; i++) {
            graph[i] = new ArrayList<>();
        }
        HashMap<String, Integer> edgeColor = new HashMap<>();
        ArrayList<String> edges = new ArrayList<>();
        for (int i = 0; i < n - 1; i++) {
            int u = in.nextInt() - 1, v = in.nextInt() - 1;
            edges.add((u + " " + v));
            graph[u].add(v);
            graph[v].add(u);

        }
        Queue<Integer> bfsQ = new LinkedList<>();
        boolean[] visited = new boolean[n];
        bfsQ.add(0);
        int maxColor = 0;
        visited[0] = true;
        int[] parentColor = new int[n];
        while (!bfsQ.isEmpty()) {
            int v = bfsQ.poll();
            int cur = 1;
            maxColor = Math.max(maxColor, graph[v].size());
            for (int u : graph[v]) {
                if (!visited[u]) {
                    if (parentColor[v] == cur)
                        cur++;
                    bfsQ.add(u);
                    visited[u] = true;
                    edgeColor.put(v + " " + u, cur);
                    edgeColor.put(u + " " + v, cur);
                    parentColor[u] = cur;
                    cur++;
                }
            }
        }
        w.println(maxColor);
        for (String x : edges) {
            w.println(edgeColor.get(x));
        }
        w.close();
    }

    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1)
                throw new UnknownError();
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new UnknownError();
                }
                if (numChars <= 0)
                    return -1;
            }
            return buf[curChar++];
        }

        public int peek() {
            if (numChars == -1)
                return -1;
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    return -1;
                }
                if (numChars <= 0)
                    return -1;
            }
            return buf[curChar];
        }

        public void skip(int x) {
            while (x-- > 0)
                read();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }

        public long nextLong() {
            return Long.parseLong(next());
        }

        public String nextString() {
            return next();
        }

        public String next() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            StringBuffer res = new StringBuffer();
            do {
                res.appendCodePoint(c);
                c = read();
            } while (!isSpaceChar(c));

            return res.toString();
        }

        public String nextLine() {
            StringBuffer buf = new StringBuffer();
            int c = read();
            while (c != '\n' && c != -1) {
                if (c != '\r')
                    buf.appendCodePoint(c);
                c = read();
            }
            return buf.toString();
        }

        public double nextDouble() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            double res = 0;
            while (!isSpaceChar(c) && c != '.') {
                if (c == 'e' || c == 'E')
                    return res * Math.pow(10, nextInt());
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            if (c == '.') {
                c = read();
                double m = 1;
                while (!isSpaceChar(c)) {
                    if (c == 'e' || c == 'E')
                        return res * Math.pow(10, nextInt());
                    if (c < '0' || c > '9')
                        throw new InputMismatchException();
                    m /= 10;
                    res += (c - '0') * m;
                    c = read();
                }
            }
            return res * sgn;
        }

        public int[] nextIntArray(int n) {
            int[] a = new int[n];
            for (int i = 0; i < n; i++)
                a[i] = nextInt();
            return a;
        }

        public long[] nextLongArray(int n) {
            long[] a = new long[n];
            for (int i = 0; i < n; i++)
                a[i] = nextLong();
            return a;
        }

        public boolean hasNext() {
            int value;
            while (isSpaceChar(value = peek()) && value != -1)
                read();
            return value != -1;
        }

        private boolean isSpaceChar(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

    }
}

Measured memory_bytes: 111608