//#define NDEBUG
#include <algorithm>
#include <cstddef>
#include <cstdint>
#include <iostream>
#include <vector>

namespace n91 {

using i8 = std::int_fast8_t;
using i32 = std::int_fast32_t;
using i64 = std::int_fast64_t;
using u8 = std::uint_fast8_t;
using u32 = std::uint_fast32_t;
using u64 = std::uint_fast64_t;
using isize = std::ptrdiff_t;
using usize = std::size_t;

struct rep {
  struct itr {
    usize i;
    constexpr itr(const usize i) noexcept : i(i) {}
    void operator++() noexcept { ++i; }
    constexpr usize operator*() const noexcept { return i; }
    constexpr bool operator!=(const itr x) const noexcept { return i != x.i; }
  };
  const itr f, l;
  constexpr rep(const usize f, const usize l) noexcept
      : f(std::min(f, l)), l(l) {}
  constexpr auto begin() const noexcept { return f; }
  constexpr auto end() const noexcept { return l; }
};
struct revrep {
  struct itr {
    usize i;
    constexpr itr(const usize i) noexcept : i(i) {}
    void operator++() noexcept { --i; }
    constexpr usize operator*() const noexcept { return i; }
    constexpr bool operator!=(const itr x) const noexcept { return i != x.i; }
  };
  const itr f, l;
  constexpr revrep(const usize f, const usize l) noexcept
      : f(l - 1), l(std::min(f, l) - 1) {}
  constexpr auto begin() const noexcept { return f; }
  constexpr auto end() const noexcept { return l; }
};
template <class T> auto md_vec(const usize n, const T &value) {
  return std::vector<T>(n, value);
}
template <class... Args> auto md_vec(const usize n, Args... args) {
  return std::vector<decltype(md_vec(args...))>(n, md_vec(args...));
}
template <class T> constexpr T difference(const T &a, const T &b) noexcept {
  return a < b ? b - a : a - b;
}
template <class T> void chmin(T &a, const T &b) noexcept {
  if (b < a)
    a = b;
}
template <class T> void chmax(T &a, const T &b) noexcept {
  if (a < b)
    a = b;
}
template <class T> T scan() {
  T ret;
  std::cin >> ret;
  return ret;
}

} // namespace n91
#include <utility>

template <class F> class fix_point : private F {
public:
  explicit constexpr fix_point(F &&f) : F(std::forward<F>(f)) {}

  template <class... Args>
  constexpr decltype(auto) operator()(Args &&... args) const {
    return F::operator()(*this, std::forward<Args>(args)...);
  }
};

template <class F> constexpr decltype(auto) make_fix(F &&f) noexcept {
  return fix_point<F>(std::forward<F>(f));
}
#include <algorithm>
#include <iostream>
#include <map>
#include <utility>

namespace n91 {

void main_() {
  /*
  std::ios::sync_with_stdio(false);
  std::cin.tie(nullptr);
  //*/
  const usize n = scan<usize>();
  auto g = md_vec(n, 0, usize());
  std::map<std::pair<usize, usize>, usize> mp;
  for (const usize i : rep(0, n - 1)) {
    const usize a = scan<usize>() - 1;
    const usize b = scan<usize>() - 1;
    g[a].push_back(b);
    g[b].push_back(a);
    mp[{a, b}] = i;
    mp[{b, a}] = i;
  }
  std::vector<usize> ans(n - 1);
  make_fix(
      [&](const auto &f, const usize v, const usize p, const usize c) -> void {
        usize ci = 1;
        for (const usize e : g[v]) {
          if (e == p) {
            continue;
          }
          if (ci == c) {
            ci += 1;
          }
          ans[mp[{v, e}]] = ci;
          f(e, v, ci);
          ci += 1;
        }
      })(0, n, n);
  std::cout << *std::max_element(ans.cbegin(), ans.cend()) << std::endl;
  for (const auto e : ans) {
    std::cout << e << std::endl;
  }
}

} // namespace n91

int main() {
  n91::main_();
  return 0;
}


Measured memory_bytes: 19840