#include <iostream>
#include <map>
#include <vector>
#include <algorithm>
#include <string>
#include <queue>
#include <iomanip>
#include <set>
#include <unordered_map>

#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

using namespace std;

#define rep(i,n) for(int i=0,i##_len=(n);i<i##_len;++i)
#define repx(i,s,e,d) for(int i=s,i##_end=(e);i<i##_end;i+=d)
#define repxr(i,s,e,d) for(int i=s,i##_end=(e);i>i##_end;i+=d)
#define rept(n) for(int ___i___=0,i##_len=(n);___i___<i##_len;++___i___)
#define repi(itr, ds) for (auto itr = ds.begin(); itr != ds.end(); itr++)
#define ALL(x) (x).begin(),(x).end()
#define SZ(x) ((int)(x).size())
#define ZERO(a) memset(a,0,sizeof(a))
#define BIT(n) (1LL<<(n))
#define UNIQUE(v) v.erase(unique(v.begin(),v.end()),v.end());
#define CEIL(x, y) (((x) + (y) - 1) / (y))

// vector
template <typename T>
istream &operator>>(istream &is, vector<T> &vec) {
    for (T &x : vec) is >> x;
    return is;
}
// pair
template <typename T, typename U>
ostream &operator<<(ostream &os, pair<T, U> &pair_var) {
    os << "(" << pair_var.first << ", " << pair_var.second << ")";
    return os;
}
// vector
template <typename T>
ostream &operator<<(ostream &os, const vector<T> &vec) {
    os << "{";
    for (int i = 0; i < vec.size(); i++) {
        os << vec[i] << (i + 1 == vec.size() ? "" : ", ");
    }
    os << "}";
    return os;
}
// map
template <typename T, typename U>
ostream &operator<<(ostream &os, map<T, U> &map_var) {
    os << "{";
    repi(itr, map_var) {
        os << *itr;
        itr++;
        if (itr != map_var.end()) os << ", ";
        itr--;
    }
    os << "}";
    return os;
}
// set
template <typename T>
ostream &operator<<(ostream &os, set<T> &set_var) {
    os << "{";
    repi(itr, set_var) {
        os << *itr;
        itr++;
        if (itr != set_var.end()) os << ", ";
        itr--;
    }
    os << "}";
    return os;
}
#define DUMPOUT cout
void dump_func() {
    DUMPOUT << endl;
}
template <class Head, class... Tail>
void dump_func(Head &&head, Tail &&... tail) {
    DUMPOUT << head;
    if (sizeof...(Tail) > 0) {
        DUMPOUT << ", ";
    }
    dump_func(std::move(tail)...);
}
#ifdef LOCAL_
#define dump(...)                                                              \
    DUMPOUT << "  " << string(#__VA_ARGS__) << ": "                            \
            << "[" << to_string(__LINE__) << ":" << __FUNCTION__ << "]"        \
            << endl                                                            \
            << "    ",                                                         \
        dump_func(__VA_ARGS__)
#else
#define dump(...)
#endif

typedef long long int lli;
typedef pair<int, int> ii;
typedef priority_queue<int, vector<int>, greater<int> > heapq;
int dx[4]={1,0,-1,0};
int dy[4]={0,1,0,-1};
struct aaa{
    aaa(){
        cin.tie(0); ios::sync_with_stdio(0); cout<<fixed<<setprecision(20);
    };
}aaaaaaa;

// #define int long long int
// struct S{
//     bool operator<(const S& x) const {
//         return ;
//     }
// };
struct Edge {
    int u, v;
    int c;
};
struct Node {
    vector<int> edges;
    int parentEdge;
};

signed main() {
    int N; cin >> N;
    vector<Node> nodes(N);
    vector<Edge> edges(N - 1);
    rep(i, N - 1) {
        int u, v; cin >> u >> v; u--; v--;
        edges[i].u = u; edges[i].v = v; edges[i].c = 0;
        nodes[u].edges.push_back(i);
        nodes[v].edges.push_back(i);
    }

    vector<int> usedV(N, 0);
    queue<int> Q;
    Q.push(0); usedV[0] = 1; nodes[0].parentEdge = -1;
    int K = 0;
    while(!Q.empty()) {
        int i = Q.front(); Q.pop();
        Node* v = &nodes[i];

        int edgeColor = 0;
        if (v->parentEdge != -1) {
            edgeColor = edges[v->parentEdge].c;
        }

        int c = edgeColor == 1 ? 2 : 1;
        for (int l: nodes[i].edges) {
            if (l == nodes[i].parentEdge) continue;
            Edge* e = &edges[l];
            int d = e->u != i ? e->u : e->v;

            if (usedV[d] == 1) continue;

            Q.push(d); usedV[d] = 1; nodes[d].parentEdge = l;
            K = max(c, K);
            edges[l].c = c;
            c++;
            if (c == edgeColor) c++;
        }
    }

    cout << K << endl;
    rep(i, N - 1) {
        cout << edges[i].c << endl;
    }
}


Measured memory_bytes: 8448