#include <bits/stdc++.h>

using namespace std;

vector <vector <int>> g;
vector <int> an;
map <pair <int, int >, int> mp;
vector <bool> used;
map <int, int > h;

void dfs(int j, int x)
{
    used[j] = 1;
    int cnt = 1;
    for (int i = 0; i < g[j].size(); ++i)
    {
        if (cnt == x)
            cnt++;
        if (!used[g[j][i]])
        {
            int r1 = mp[{j, g[j][i]}];
            int r2 = mp[{g[j][i],j}];
            int a = max(r1, r2);
            an[a] = cnt;
            dfs(g[])
            cnt++;
        }
    }
}

int main()
{
    int n, m, a, b;
    cin >> n >> m;
    g.resize(n + 1);
    an.resize(m + 1);
    used.resize(n + 1);
    for (int i = 0; i < m; ++i)
    {
        cin >> a >> b;
        g[a].push_back(b);
        g[b].push_back(a);
        mp[{a,b}] = i;
    }
    int ans = 0;
    for (int i = 1; i <= n; ++i)
        ans = max(ans, (int)g[i].size());
    cout << ans << endl;
    dfs(1, 0);
    for (int i = 0; i < an.size(); ++i)
        cout << an[i] << " ";
    return 0;
}