#include <cstdio>
#include <vector>
#include <utility>
#include <map>
using namespace std;
typedef pair<int, int> pt;
vector< vector< int > > T;
vector< pt > Vhod;
map< pt, int > Color;
int maxColor = 1;

void solve(int root, int prevColor)
{
	int color = 1;
	for(int i = 0; i < T[root].size(); i++)
	{
		pt u_v = make_pair(root, T[root][i]);
		if(color == prevColor)
			color++;
		
		if(color > maxColor)
			maxColor = color;

		Color[u_v] = color++;
		solve(u_v.second, Color[u_v]);
	}
}

int main()
{
	freopen("tcoloring.in", "r", stdin);
	freopen("tcoloring.out", "w", stdout);
	int N, u, v;
	scanf("%d", &N);
	T.resize(N + 100);
	for(int i = 0; i < N - 1; i++)
	{
		scanf("%d%d", &u, &v);
		Vhod.push_back(make_pair(u, v));
		T[u].push_back(v);
	}
	solve(1, 0);
	printf("%d\n", maxColor);
	for(int i = 0; i < Vhod.size(); i++)
	{
		printf("%d\n",Color[Vhod[i]]);
	}
	return 0;
}