#include <algorithm>
#include <cassert>
#include <cctype>
#include <cmath>
#include <cstdio>
#include <ctime>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unordered_map>
#include <vector>

using namespace std;
using ll = long long;

#define REP(i, a) for (int i = 0; i < (a); ++i)
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define FORR(i, a, b) for (int i = (a)-1; i >= (b); --i)
#define ALL(obj) (obj).begin(), (obj).end()
#define SIZE(obj) (int)(obj).sizeT()
#define YESNO(cond, yes, no)                                                   \
    { cout << ((cond) ? (yes) : (no)) << endl; }
#define SORT(list) sort(ALL((list)));
#define RSORT(list) sort((list).rbegin(), (list).rend())
#define ASSERT(cond, mes) assert(cond&& mes)

constexpr int MOD = 1'000'000'007;
constexpr int INF = 1'050'000'000;

template <typename T>
T round_up(const T& a, const T& b) {
    return (a + (b - 1)) / b;
}

template <typename T1, typename T2>
istream& operator>>(istream& is, pair<T1, T2>& p) {
    is >> p.first >> p.second;
    return is;
}

template <typename T1, typename T2>
ostream& operator<<(ostream& os, pair<T1, T2>& p) {
    os << p.first << p.second;
    return os;
}

template <typename T>
istream& operator>>(istream& is, vector<T>& v) {
    REP(i, (int)v.size())
        is >> v[i];
    return is;
}

template <typename T>
T clamp(T& n, T a, T b) {
    if (n < a) n = a;
    if (n > b) n = b;
    return n;
}

template <typename T>
static T GCD(T u, T v) {
    T r;
    while (v != 0) {
        r = u % v;
        u = v;
        v = r;
    }
    return u;
}

template <typename T>
static T LCM(T u, T v) {
    return u / GCD(u, v) * v;
}

template <class T>
std::vector<T> enum_div(T n) {
    std::vector<T> ret;
    for (T i = 1; i * i <= n; i++) {
        if (n % i == 0) {
            ret.push_back(i);
            if (i * i != n) { ret.push_back(n / i); }
        }
    }
    return ret;
}

bool isPrime(ll num) {
    if (num < 2)
        return false;
    else if (num == 2)
        return true;
    else if (num % 2 == 0)
        return false;

    for (ll i = 3; i * i <= num; i += 2) {
        if (num % i == 0) { return false; }
    }

    return true;
};

template <typename T>
bool chmin(T& a, const T& b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}

template <typename T>
bool chmax(T& a, const T& b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}

template <class T>
bool is_integer(T x) {
    return std::floor(x) == x;
}

struct ToUpper {
    char operator()(char c) { return toupper(c); }
};

struct ToLower {
    char operator()(char c) { return tolower(c); }
};

struct Edge {
    int to, id;
};

int N;
vector<vector<Edge>> G;
vector<int> ans;
int K;


//v:今の頂点
//p:どこから来たか
void dfs(int v, int c = -1, int p = -1) {
    //1からスタートすれば色の上限を超える前に終了する
    int k = 1;
    REP(i, G[v].size()) {
        int u = G[v][i].to;
        int ei = G[v][i].id;
        //親に向かわないように
        if (u == p)continue;
        //同じ色なら色を変える
        if (k == c)k++;
        ans[ei] = k; k++;
        dfs(u, ans[ei], v);
    }
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(20);

    cin >> N;
    G.resize(N);
    ans.resize(N - 1);
    REP(i, N - 1) {
        int a, b;
        cin >> a >> b;
        a--; b--;
        G[a].emplace_back(Edge{ b,i });
        G[b].emplace_back(Edge{ a,i });
    }

    for (auto&& g : G) {
        K = max(K, (int)g.size());
    }
    dfs(0);


    cout << K << endl;
    REP(i, ans.size()) {
        cout << ans[i] << endl;
    }
    return 0;
}


Measured memory_bytes: 8320