#include<iostream>
#include<cstdio>
#include<algorithm>
#include<vector>
using namespace std;
long long i,z[301],maxk,n,x,y,used[301],m;
bool colors[301][301];
vector<pair<long long, long long> > v[301];
void color(long long p)
{
    if(used[p]==1) return;
    used[p]=1;
    int m=v[p].size();
    int k=1;
    for(int i=0; i<=m-1; i++)
    {
        k=1;
        if(used[v[p][i].first]==1) {continue;}
        while(colors[p][k]==1||colors[v[p][i].first][k]==1) k++;
        colors[p][k]=colors[v[p][i].first][k]=1;
        z[v[p][i].second]=k;
        if(maxk<k) maxk=k;
    }
    for(int i=0; i<=m-1; i++)
    {
        if(used[v[p][i].first]==1) {continue;}
        color(v[p][i].first);
    }
    return ;
}
int main()
{
    freopen("gcoloring.in","r",stdin);
    freopen("gcoloring.out","w",stdout);
	scanf("%lld%lld",&n,&m);
	for(i=1; i<=m; i++)
	{
	    scanf("%lld%lld",&x,&y);
	    v[x].push_back(make_pair(y,i));
	    v[y].push_back(make_pair(x,i));
	}
	color(1);
	printf("%lld\n",maxk);
	for(i=1; i<=m; i++)
	{
	    printf("%lld\n",z[i]);
	}
	return 0;
}