#include <stdio.h>
#include <cstring>
#include <fstream>
#include <vector>
#include <iostream>

using namespace std;

class Node{
public:
	std::vector<Node*> nodes;
	std::vector<int*> edges;
};

vector<int> edges;
vector<Node> nodes;
int N,E;

int getMinPssible(Node* current,Node* follow)
{
	int minPossible = 1;
	for(int k = 1; k <= 301; k++){
		for(int i = 0; i < current->edges.size(); i++){
			if ( *(current->edges[i]) == k ){
				goto next;
			}
		}
		for(int i = 0; i < follow->edges.size(); i++){
			if ( *(follow->edges[i]) == k ){
				goto next;
			}
		}
		minPossible = k;
		break;

next: ;

	}

	return minPossible;
}

bool allLinksUsed(Node* node)
{
	for(int i = 0; i < node->nodes.size(); i++){
		if ( node->edges[i] == 0 ){
			return false;
		}
	}
	return true;
}

int solve(Node* parent, Node* current)
{
	int maxUsedColor = 0;
	for(int i = 0; i < current->nodes.size(); i++){
		if ( current->nodes[i] != parent ){
			int minPossible = getMinPssible(current, current->nodes[i]);
			*(current->edges[i]) = minPossible ;
			maxUsedColor = std::max(maxUsedColor, minPossible);
			if ( !allLinksUsed(current->nodes[i]) ){
				maxUsedColor = std::max(maxUsedColor, solve(current, current->nodes[i]));
			}
		}
	}

	return maxUsedColor;
}

int main()
{
	ifstream in("gcoloring.in");
	in >> N;
	in >> E;

	nodes.resize(N+1);
	edges.resize(E);

	for(int i = 0; i < E; i++){
		int A,B;
		in >> A >> B;
		edges[i] = 0;
		nodes[A].nodes.push_back(&nodes[B]);
		nodes[B].nodes.push_back(&nodes[A]);
		nodes[A].edges.push_back(&edges[i]);
		nodes[B].edges.push_back(&edges[i]);
	}

	int maxUsed = solve(0, &nodes[1]);

	ofstream out("gcoloring.out");
	out << maxUsed << endl;

	for(int i = 0; i < edges.size(); i++){
		out << edges[i] << endl;
	}
	return 0;
}