#include<bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<ll, ll> pll;
typedef pair<ull, ull> pullull;
typedef pair<ll, int> plli;
typedef pair<int, pii> pipii;
typedef vector<vector<int> > mati;
typedef vector<vector<double> > matd;
typedef vector<ll> vll;
typedef vector<vector<ll>> vvll;
typedef vector<vector<vector<ll>>> vvvll;
typedef vector<bool> vb;
typedef vector<vector<bool>> vvb;
typedef vector<vector<vector<bool>>> vvvb;
typedef vector<pll> vpll;
typedef vector<vpll> vvpll;

#define FOR(i,x,y) for(ll i=(ll)x; i<(ll)y; ++i)
#define REP(i,y) FOR(i, 0, y)
#define RFOR(i,x,y) for(ll i=(ll)x; i>=(ll)y; --i)
#define RREP(i,x) RFOR(i, x, 0)
#define ALL(a) a.begin(), a.end()
#define pb push_back
#define debug_printf(x...) cerr << "line " << __LINE__ << " : "; debug_printf_in(x);

template <typename First>
void debug_printf_in(First first){
  cerr << first << endl;
  return;
}

template <typename First, typename... Rest>
void debug_printf_in(First first, Rest... rest){
  cerr << first << " ";
  debug_printf_in(rest...);
  return;
}

void IN(void){
  return;
}

template <typename First, typename... Rest>
void IN(First& first, Rest&... rest){
  cin >> first;
  IN(rest...);
  return;
}

template <typename First>
void OUT(First first){
  cout << first << endl;
  return;
}

template <typename First, typename... Rest>
void OUT(First first, Rest... rest){
  cout << first << " ";
  OUT(rest...);
  return;
}

template<class t, class u> void chmax(t&a,u b){if(a<b)a=b;};
template<class t, class u> void chmin(t&a,u b){if(a>b)a=b;};
int popcount(int t){return __builtin_popcount(t);} //GCC
int popcount(ll t){return __builtin_popcountll(t);} //GCC

template <typename T>
void vec_print(vector<T> VEC){
  REP(i, VEC.size()){
    cout << VEC[i] << " ";
  }
  cout << "\n";
};

template <typename T>
void mat_print(vector<vector<T> > MAT){
  REP(i, MAT.size()){
    REP(j, MAT[i].size()){
      cout << MAT[i][j] << " ";
    }
    cout << "\n";
  }
};

template <typename CLASS1, typename CLASS2>
class HOGE{
  public:
    CLASS1 key;
    CLASS2 value;
    HOGE(void){
      return;
    };
    HOGE(CLASS1 key, CLASS2 value){
      this->key = key;
      this->value = value;
    };
    ~HOGE(void){
      return;
    };

    void print(void){
      cout << "key : " << key << ", value : " << value << "\n";
      return;
    };
    
    bool operator==(const HOGE &obj){
      return (this->value == obj.value);
    };
    bool operator<(const HOGE &obj){
      return (this->value < obj.value);
    };
    bool operator>(const HOGE &obj){
      return (this->value > obj.value);
    };
};

template <typename CLASS1, typename CLASS2>
bool operator==(const HOGE<CLASS1, CLASS2> &hoge1, const HOGE<CLASS1, CLASS2> &hoge2){
  return hoge1.value == hoge2.value;
};

template <typename CLASS1, typename CLASS2>
bool operator<(const HOGE<CLASS1, CLASS2> &hoge1, const HOGE<CLASS1, CLASS2> &hoge2){
  return hoge1.value < hoge2.value;
};

template <typename CLASS1, typename CLASS2>
bool operator>(const HOGE<CLASS1, CLASS2> &hoge1, const HOGE<CLASS1, CLASS2> &hoge2){
  return hoge1.value > hoge2.value;
};

constexpr int INF = (1<<30);
constexpr ll INFLL = 1LL<<62;
constexpr long double EPS = 1e-12;
constexpr ll MOD = (ll)((1E+9)+7);

int main(){
  cin.tie(0); // cut the cin and cout (default, std::flush is performed after std::cin)
  ios::sync_with_stdio(false); // cut the iostream and stdio (DON'T endl; BUT "\n";)

  ll N;
  IN(N);
  vpll Edge(N-1);
  map<pair<ll, ll>, ll> mp;
  vvll Graph(N);
  REP(i,N-1){
    ll a, b;
    IN(a,b);
    a--; b--;
    if(a>b) swap(a,b);
    Edge[i] = make_pair(a, b);
    Graph[a].pb(b);
    Graph[b].pb(a);
    mp[make_pair(a, b)] = i;
  }

  ll K = 0;
  REP(i,N) chmax(K, Graph[i].size());

  vll color(N-1, 0);
  queue<ll> que;
  que.push(0);
  vb touch(N, false);
  touch[0] = true;
  vll flag(K+1, 0);
  while(!que.empty()){
    ll pos = que.front(); que.pop();
    REP(i,K+1) flag[i] = 0;
    REP(i,Graph[pos].size()){
      ll npos = Graph[pos][i];
      ll a = min(pos, npos);
      ll b = max(pos, npos);
      ll c = color[mp[make_pair(a, b)]];
      flag[c]++;
    }
    ll color_tmp = 1;
    while(flag[color_tmp]) color_tmp++;
    REP(i,Graph[pos].size()){
      ll npos = Graph[pos][i];
      ll a = min(pos, npos);
      ll b = max(pos, npos);
      ll c = color[mp[make_pair(a, b)]];
      if(c>0) continue;
      color[mp[make_pair(a, b)]] = color_tmp;
      color_tmp++;
      while(flag[color_tmp]) color_tmp++;
      que.push(npos);
    }
  }

  printf("%lld\n", K);
  REP(i,N-1){
    printf("%lld\n", color[i]);
  }

  return 0;
}


Measured memory_bytes: 15232