#define _CRT_SECURE_NO_DEPRECATE
#include <iostream>
#include <string>
#include <vector>
#include <sstream>
#include <queue>
#include <algorithm>
#include <iomanip>
#include <map>
#include <set>
#include <math.h>
#include <stack>
#include <deque>
#include <numeric>
#include <cstring>
#include <cstdio>
#include <cstdlib>
#include <bitset>

//#define all(v) v.begin(),v.end()
using namespace std;
//typedef long long ll;
//typedef unsigned long long ull;
//typedef long double ld;
//const ld epsylon = 1e-9;
//typedef unsigned int ui;
//inline long double get_time(){   
// return (long double)clock()/CLOCKS_PER_SEC;
//};
//ld start_time,end_time;

int n, tree[10001][10001], colors, razklon[10001];
bool more();

int main()
{
	freopen("tcoloring.in","r",stdin);
	freopen("tcoloring.out","w",stdout);
	//start_time = get_time();
	//program
	memset(tree, 0, sizeof(tree));
	memset(razklon, 0, sizeof(razklon));
	scanf("%d", &n);
	int from, to;
	int maxrazk = 0;
	for (int i = 0; i < n - 1; ++i)
	{
		scanf("%d %d", &from, &to);
		tree[from][to]++;
		razklon[i]++;
		maxrazk = max(razklon[i], maxrazk);
	}
	colors = maxrazk;
	if (more())
	{
		colors++;
	}
	printf("%d\n",colors);
	int k = 0;
	for(int i = 1; i <= n; ++i)
	{
		k = 1;
		for (int j = 1; j <= n; j++)
		{
			if (tree[i][j])
			{
				if (i == 1) tree[i][j] = k++;
				else if (i % 2 == 0 && k == 1) {tree[i][j] = 2; k = 2; printf("%d\n",tree[i][j]);}
				else if (i % 2 == 0 && k != 1) {tree[i][j] = tree[i][j] = k-1; k++; printf("%d\n",tree[i][j]);}
				else if (i % 2 && k == 1) {tree[i][j] = 1; k = 1; printf("%d\n",tree[i][j]);}
				else if (i % 2 && k != 1) {tree[i][j] = ++k; printf("%d\n",tree[i][j]);}
			}
		}
	}
	//end program
	//end_time=get_time()-start_time;
	return 0;
}

bool more(){
	int cnt = 0, red = 0;bool first = true;
	for (int i = 1; i <= n; ++i)
	{
		if (first)
		{
			if (razklon[i] == colors) {cnt++; red = i; first = false; continue;}
		}
		if (razklon[i] == colors && red == i-1) {cnt++; red = i;}
		else if (razklon[i] == colors) {red = i;}
	}
	if (cnt > 1) return true;
	else return false;
}