#include <bits/stdc++.h>
#define loop(n) for (int ngtkana_is_a_genius = 0; ngtkana_is_a_genius < int(n); ngtkana_is_a_genius++)
#define rep(i, begin, end) for (int i = int(begin); (i) < int(end); i++)
#define all(v) v.begin(), v.end()
#define rand(l, r) std::uniform_int_distribution<>(l, r)(mt)
using lint = long long;
auto mt = std::mt19937_64(std::random_device{}());
auto cmn = [](auto& a, auto b){ if (a > b) {a = b; return true;} return false; };
auto cmx = [](auto& a, auto b){ if (a < b) {a = b; return true;} return false; };
void debug_impl() { std::cerr << std::endl; }
template <typename Head, typename... Tail>
void debug_impl(Head head, Tail... tail) { std::cerr << " " << head; debug_impl(tail...); }
#ifndef STOPIT
#define debug(...)\
  do {\
    std::cerr << std::boolalpha << "[" << #__VA_ARGS__ << "]:";\
    debug_impl(__VA_ARGS__);\
    std::cerr << std::noboolalpha;\
  } while (false)
#else
#define debug(...) 0;
#endif

template < typename Container, typename Value = typename Container::value_type, std::enable_if_t<!std::is_same< Container, std::string >::value, std::nullptr_t> = nullptr>
std::istream& operator>> (std::istream& is, Container& v)
  { for (auto & x : v) { is >> x; } return is; }

template < typename Container, typename Value = typename Container::value_type, std::enable_if_t<!std::is_same< Container, std::string >::value, std::nullptr_t> = nullptr >
std::ostream& operator<< (std::ostream& os, Container const& v) {
 os << "{";
  for (auto it = v.begin(); it != v.end(); it++)
    {os << (it != v.begin() ? "," : "") << *it;}
  return os << "}";
}

template <typename T>
auto make_vector_impl(size_t sz, T t) {return std::vector<T>(sz, t);}

template <size_t N, typename T, typename U, std::enable_if_t<N == 1, std::nullptr_t> = nullptr>
auto make_vector(size_t sz, U u) {return make_vector_impl(sz, T(u));}

template <size_t N, typename T, std::enable_if_t<N == 1, std::nullptr_t> = nullptr>
auto make_vector(size_t sz) {return std::vector<T>(sz);}

template <size_t N, typename T, typename... Args, std::enable_if_t<N != 1, std::nullptr_t> = nullptr>
auto make_vector(size_t a, Args... args) {return make_vector_impl(a, make_vector<N - 1, T>(args...));}

template <typename T, typename Size_t>
auto& at(T& t, Size_t i) {return t.at(i);}

template <typename T, typename Size_t, typename... Args>
auto& at(T& t, Size_t i, Args... args) {return at(t.at(i), args...);}

template < template < typename ... > class Tuple,  typename... Args, std::size_t ... Inds, std::size_t = std::tuple_size< Tuple < Args ... > >::value >
std::istream& tuple_input_impl(std::istream& os, Tuple<Args...>& tuple, std::integer_sequence<std::size_t, Inds...>)
  { (void)std::initializer_list<int>{((void)(os >> std::get< Inds >(tuple)), 0)...}; return os; }
template < template < typename ... > class Tuple,  typename... Args, std::size_t = std::tuple_size< Tuple < Args ... > >::value >
std::istream& operator>> (std::istream& os, Tuple<Args...>& tuple)
  { return tuple_input_impl(os, tuple, std::index_sequence_for<Args...>()); }

template < template < typename ... > class Tuple,  typename... Args, std::size_t ... Inds, std::size_t = std::tuple_size< Tuple < Args ... > >::value >
std::ostream& tuple_output_impl(std::ostream& os, const Tuple<Args...>& tuple, std::integer_sequence<std::size_t, Inds...>)
  { os << "("; (void)std::initializer_list<int>{((void)(os << (Inds > 0 ? "," : "") << std::get< Inds >(tuple)), 0)...}; return os << ")"; }
template < template < typename ... > class Tuple,  typename... Args, std::size_t = std::tuple_size< Tuple < Args ... > >::value >
std::ostream& operator<< (std::ostream& os, const Tuple<Args...>& tuple)
 { return tuple_output_impl(os, tuple, std::index_sequence_for<Args...>()); }

template< typename F >
class fixed_point : F {
  public:
    explicit constexpr fixed_point (F&& f) noexcept
      : F(std::forward< F >(f)) {}
    template< typename ... Args >
    constexpr decltype(auto) operator()(Args&& ... args) const
      { return F::operator()(*this, std::forward< Args >(args)...); }
};
template< typename F >
static inline constexpr decltype(auto) fix (F&& f) noexcept
  { return fixed_point< F >{std::forward< F >(f)}; }

int main() {
  std::cin.tie(0); std::cin.sync_with_stdio(false);
  int n; std::cin >> n;
  auto graph = make_vector< 2, std::pair< int, int > >(n,0);
  rep(i,0,n-1) {
    int u, v; std::cin >> u >> v;
    u--, v--;
    graph.at(u).emplace_back(v, i);
    graph.at(v).emplace_back(u, i);
  }
  std::vector< int > ans(n-1,-1);
  fix([&](auto&& dfs, int crr, int prv, int color) -> void {
    // debug(crr, color);
    int counter = 0;
    for (auto edge : graph.at(crr)) {
      int nxt, id; std::tie(nxt, id) = edge;
      if (nxt == prv) continue;
      if (counter == color) counter++;
      ans.at(id) = counter;
      dfs(nxt, crr, counter);
      counter++;
    }
  })(0, 0, -1);
  int kind = 1 + *std::max_element(all(ans));
  for (int& x : ans) x++;
  std::cout << kind << std::endl;
  for (int x : ans) {
    std::cout << x << std::endl;
  }
  return 0;
}

Measured memory_bytes: 6912