#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 mpair make_pair
#define all(v) v.begin(),v.end()
using namespace std;
typedef long long ll;
typedef long double ld;
const ld epsylon = 1e-9;
vector<int> cols;
char used[302][302];
vector<char> vis;
int n,m;
vector<vector<pair<int, int> > > ne;
int ans;

void dfs(int from) {
	vis[from] = 1;
	for (int i  = 0; i < (int)ne[from].size();++i){
		if (cols[ne[from][i].second] != -1) {
			continue;
		}
		int fc = 0;
		for (int j = 1; j <= ans; ++j) {
			if (!used[from][j] && !used[ne[from][i].first][j]) {
				fc = j;
				break;
			}
		}

		cols[ne[from][i].second] = fc;
		used[from][fc] = 1;
		used[ne[from][i].first][fc] = 1;
		if (!vis[ne[from][i].first]){
			vis[ne[from][i].first] = 1;
			dfs(ne[from][i].first);
		}
	}
}
int main()
{
	freopen("gcoloring.in","r",stdin);
	freopen("gcoloring.out","w",stdout);
	cin >> n >>m;
	ne.resize(n);
	for (int i = 0; i < m;++i){
		int f,t;
		scanf("%d %d",&f, &t);
		f--;
		t--;
		ne[f].push_back(mpair(t, i));
		ne[t].push_back(mpair(f, i));
	}
	ans = 0;
	for (int i = 0; i < n ;++i){
		ans = max(ans, (int)ne[i].size());
	}
	cols.resize(m, -1);
	memset(used, 0, sizeof(used));
	int beg;
	for (int i = 0; i < (int)ne.size();++i){
		if (ne[i].size() == ans) {
			beg = i;
			break;
		}
	}
	queue<int> tc;
	vis.resize(n, 0);
	//tc.push(beg);
	dfs(beg);
	//vis[beg] = 1;
	//for (int i = 0; i < (int)ne[beg].size(); ++i) {
	//	cols[ne[beg][i].second] = i + 1;
	//}
	//while (!tc.empty()) {
	//	int c = tc.front();tc.pop();
	//	int color = 1;
	//	for (int i  = 0; i < (int)ne[c].size();++i){
	//		if (cols[ne[c][i].second] != -1) {
	//			continue;
	//		}
	//		int fc = 0;
	//		for (int j = 1; j <= ans; ++j) {
	//			if (!used[c][j] && !used[ne[c][i].first][j]) {
	//				fc = j;
	//				break;
	//			}
	//		}

	//		cols[ne[c][i].second] = fc;
	//		used[c][fc] = 1;
	//		used[ne[c][i].first][fc] = 1;
	//		if (!vis[ne[c][i].first]){
	//			tc.push(ne[c][i].first);
	//			vis[ne[c][i].first] = 1;
	//		}
	//	}
	//}
	printf("%d\n", ans);
	for (int i  =0 ; i < (int)cols.size();++i){
		printf("%d\n", cols[i]);
	}
	return 0;
}