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

class Main{
    static HashMap<Pair, Integer> colors;
    static ArrayList<Integer> edges[];
    public static void main(String[] args){
        FastScanner fsc=new FastScanner();
        int n=fsc.nextInt();
        edges=new ArrayList[n];
        for(int i=0;i<n;i++) edges[i]=new ArrayList<Integer>();
        Pair[] pairs=new Pair[n-1];
        for(int i=0;i<n-1;i++){
            int a=fsc.nextInt()-1, b=fsc.nextInt()-1;
            edges[a].add(b);
            edges[b].add(a);
            pairs[i]=new Pair(a, b);
        }
        fsc.close();
        int maxV=0;
        int dim=0;
        for(int i=0;i<n;i++){
            if(edges[i].size()>dim){
                dim=edges[i].size();
                maxV=i;
            }
        }
        colors=new HashMap<>();
        int root=maxV;
        coloring(root, -1, 0);
        System.out.println(dim);
        for(int i=0;i<n-1;i++) System.out.println(colors.get(pairs[i]));
    }
    static void coloring(int v, int parent, int color){
        int c=1;
        for(int u:edges[v]){
            Pair pair=new Pair(u, v);
            if(u!=parent){
                if(color==c) c++;
                colors.put(pair, c);
                coloring(u, v, c);
                c++;
            }
        }
    }
    static class Pair{
        int id1;
        int id2;
        public Pair(int id1, int id2){
            this.id1=id1;
            this.id2=id2;
        }
        @Override public boolean equals(Object o){
            if(! (o instanceof Pair)) return false;
            Pair p=(Pair) o;
            if((p.id1==id1 && p.id2==id2) || (p.id1==id2 && p.id2==id1)) return true;
            else return false;
        }
        @Override public int hashCode(){
            int res=17;
            res=((res*31+id1)*31+id2)+((res*31+id2)*31+id1);
            return res;
        }
    }
    static 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: 69852