#include <iostream>
#include <fstream>
#include <cmath>

using namespace std;
    int* edges;
    int* inputs;
    int* ids;
    int* numEdges;
    int* numEdges2;
    int* order;
    int* result;
    int colors;

    int N;
    
    void dfs(int id, int col, int from) {
        int color = 0;
        for(int i=0;i<numEdges[id];i++) {
            int index = ids[id]+i;
            int k = edges[index];
            if(k==from)continue;
            int j;
            for(j=0;j<numEdges[k];j++) {
                if(edges[ids[k]+j]==id)break;
            }
            int index2 = ids[k]+j;
            
            if(color==col)color++;
            result[index] = result[index2] = color;
            dfs(k,color,id);
            
            color++;
        }
    }


    int main() {
		ofstream fout ("tcoloring.out");
		ifstream fin ("tcoloring.in");
        colors = 0;
        fin>>N;
        edges = new int[N*2-2];
        numEdges =  new int[N];
        numEdges2 = new int[N];
        ids = new int[N];
        order = new int[(N-1)*2];
        inputs = new int[(N-1)*2];
        result = new int[(N-1)*2];
		
		for(int i=0;i<N;i++) {
			numEdges[i]=numEdges2[i]=ids[i]=0;
		}

		for(int i =0;i<N-1;i++) {
			int i1=i*2;
			int i2=i*2+1;
			order[i1]=order[i2]=0;
			edges[i1]=edges[i2]=0;
			inputs[i1]=inputs[i2]=0;
			result[i1]=result[i2]=0;
		}

        for(int i =0;i<N-1;i++) {
			int j,k;
            fin>>j;
            fin>>k;
            j--;
            k--;
            inputs[i*2] = j;
            inputs[i*2+1] = k;
            numEdges[j]++;
            numEdges[k]++;
            colors = max(colors,max(numEdges[j],numEdges[k]));
        }
        
        for(int i=1;i<N;i++) {
            ids[i] = ids[i-1]+numEdges[i-1];
        }
        
        for(int i=0;i<N-1;i++) {
            int j=inputs[i*2];
            int k=inputs[i*2+1];
            order[ids[j]+numEdges2[j]] = i;
            order[ids[k]+numEdges2[k]] = i;
            edges[ids[j]+numEdges2[j]] = k;
            edges[ids[k]+numEdges2[k]] = j;
            numEdges2[j]++;
            numEdges2[k]++;
        }
        
        dfs(0,-1,-1);


        
        int* answers = new int[N-1];
        
        for(int i=0;i<N-1;i++) {
            int j=inputs[i*2];
            int k=inputs[i*2+1];
            int ii;
            for(ii=0;ii<numEdges[j];ii++) {
                if(edges[ids[j]+ii] == k)break;
            }
            answers[i]=result[ids[j]+ii]+1;
        }

        fout<<colors<<endl;
        for(int i=0;i<N-1;i++) {
           fout<<answers[i]<<endl; 
        }
		return 0;
	}