#include <algorithm>
#include <iostream>
#include <fstream>
#include <sstream>
#include <vector>
#include <bitset>
#include <deque>
#include <queue>
#include <stack>
#include <list>
#include <map>
#include <set>
#include <cmath>
#include <limits>
#include <random>
#include <numeric>
#include <iomanip>
#include <cstdlib>
#include <iterator>
#include <functional>
#include <unordered_map>
#include <unordered_set>

using namespace std;

typedef unsigned                    ui;
typedef int                         si;
typedef long                        sl;
typedef long long                   ll;
typedef unsigned long long          ull;

// ----------------

template <typename A, typename B>
string to_string(pair<A, B> p);

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);

string to_string(const string& s) {
  return '"' + s + '"';
}

string to_string(const char* s) {
  return to_string((string) s);
}

string to_string(const char ch) {
    string str;
    str.push_back('\'');
    str.push_back(ch);
    str.push_back('\'');
    return str;
}

string to_string(bool b) {
  return (b ? "true" : "false");
}

string to_string(vector<bool> v) {
  bool first = true;
  string res = "{";
  for (int i = 0; i < static_cast<int>(v.size()); i++) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(v[i]);
  }
  res += "}";
  return res;
}

template <size_t N>
string to_string(bitset<N> v) {
  string res = "";
  for (size_t i = 0; i < N; i++) {
    res += static_cast<char>('0' + v[i]);
  }
  return res;
}

template <typename A>
string to_string(A v) {
  bool first = true;
  string res = "{";
  for (const auto &x : v) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(x);
  }
  res += "}";
  return res;
}

template <typename A, typename B>
string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ")";
}

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}

void debug_out() { cerr << endl; }

template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
  cerr << " " << to_string(H);
  debug_out(T...);
}

#ifdef LOCAL
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif

// ----------------

bool Random() {
    std::random_device r;
    std::default_random_engine e1(r());
    std::uniform_int_distribution<int> n_dist(1, 5);

    ll n = n_dist(e1);

    return true;
}


template <typename T>
struct PairHash {
  size_t operator() (const pair<T, T>& v) const {
    return hash<ll>()((static_cast<ll>(v.first)) ^ (static_cast<ll>(v.second)) << 32);
  }
};

unordered_map<pair<int, int>, int, PairHash<int>> result;
vector<vector<int>> g;
vector<char> used;
vector<unordered_set<int>> colors;
int max_deg = 0;

class Item {
public:
    int V = 0;
    int C = 0;
};

void bfs() {
    queue<Item> q;
    q.push(Item{0, 0});

    while (!q.empty()) {
        Item v = q.front();
        q.pop();

        used[v.V] = true;

        // vector<int> next_colors;
        // int color_p = 1;
        // for (int i = 0; i < g[v.V].size(); ++i) {
        //     const int next_vertex = g[v.V][i];
        //     if (used[next_vertex]) {
        //         continue;
        //     }
        //
        //     int next_color = -1;
        //     for (; color_p <= max_deg; ++color_p) {
        //         if (v.C == color_p) {
        //             continue;
        //         }
        //         next_color = color_p;
        //         break;
        //     }
        //
        //     next_colors.emplace_back(next_color);
        //     color_p += 1;
        // }

        int color_p = 1;
        for (int i = 0; i < g[v.V].size(); ++i) {
            const int next_vertex = g[v.V][i];
            if (used[next_vertex]) {
                continue;
            }

            int next_color = -1;
            for (; color_p <= max_deg; ++color_p) {
                if (v.C == color_p) {
                    continue;
                }
                next_color = color_p;
                break;
            }
            color_p += 1;

            Item u;
            {
                u.V = next_vertex;
                u.C = next_color;

                debug(v.V, v.C, u.V, u.C);

                result[pair<int, int>(min(v.V, u.V), max(v.V, u.V))] = u.C;
            }

            q.push(u);
        }
    }
}

int main(int argc, char *argv[])
{
    std::ios_base::sync_with_stdio(false);

    ll n;
    cin >> n;

    vector<int> deg(n, 0);
    vector<pair<int, int>> edges;

    g.resize(n);
    for (int i = 0; i + 1 < n; ++i) {
        ll u, v;
        cin >> u >> v;
        --u, --v;

        g[v].emplace_back(u);
        g[u].emplace_back(v);

        deg[u] += 1;
        deg[v] += 1;

        max_deg = max(max_deg, deg[u]);
        max_deg = max(max_deg, deg[v]);

        edges.emplace_back(u, v);
    }

    debug(max_deg);

    used.resize(n, false);
    bfs();

    cout << max_deg << endl;
    for (const pair<int, int>& edge : edges) {
        cout << (result[pair<int, int>(min(edge.first, edge.second), max(edge.first, edge.second))]) << endl;
    }

    return 0;
}


Measured memory_bytes: 13048