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

class Main{
    public static void main(String[] args){
        FastScanner fsc=new FastScanner();
        int n=fsc.nextInt();
        ArrayList<Integer> edges[]=new ArrayList[n];
        long[] pairs=new long[n-1];
        int[] pcol=new int[n];
        for(int i=0;i<n-1;i++){
            int a=fsc.nextInt()-1, b=fsc.nextInt()-1;
            if(edges[a]==null) edges[a]=new ArrayList<Integer>();
            edges[a].add(b);
            pairs[i]=(long)a*n+b;
        }
        fsc.close();
        HashMap<Long, Integer> colors=new HashMap<>();
        int dim=0;
        for(int v=0;v<n;v++){
            if(edges[v]==null) continue;
            int c=0;
            for(int u:edges[v]) colors.put((long)v*n+u, pcol[u]=pcol[v]==++c?++c:c);
            if(c>dim) dim=c;
        }
        PrintWriter pw=new PrintWriter(System.out);
        StringBuilder sb=new StringBuilder();
        sb.append(dim).append("\n");
        for(int i=0;i<n-1;i++) sb.append(colors.get(pairs[i])).append("\n");
        pw.write(sb.toString()); pw.flush();
    }
}
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());}
    public void close(){
        try{in.close();}
        catch(IOException e){e.printStackTrace();}
    }
}

Measured memory_bytes: 53048