#include <bits/stdc++.h>
using namespace std;
long long int inline power(long long int x, long long int y,
                           long long int mod = 1e9 + 7) {
  long long int res = 1;
  while (y > 0) {
    if (y & 1) res = (res * x) % mod;
    y = y >> 1;
    x = (x * x) % mod;
  }
  return res % mod;
}
vector<int> ans, type;
void print(vector<int> v) {
  cout << *max_element(v.begin(), v.end()) << '\n';
  for (auto it : v) cout << it << ' ';
  cout << '\n';
}
bool all_distinct() {
  for (int i = 1; i < type.size(); i += 1) {
    if (type[i] == type[i - 1]) return false;
  }
  return type[0] != type.back();
}
vector<vector<int>> graph;
vector<int> vis;
void dfs(int node, int par, int col = 1) {
  if (vis[node] != 0) return;
  ans[node] = col;
  vis[node] = 1;
  for (auto child : graph[node]) {
    if (child != par) {
      dfs(child, node, 3 - col);
    }
  }
}
void solve() {
  int n;
  cin >> n;
  type.resize(n);
  ans.resize(n, 0);
  vis.resize(n);
  fill(vis.begin(), vis.end(), 0);
  for (auto &it : type) cin >> it;
  set<int> colors = {2, 3};
  ans[0] = 1;
  if (count(type.begin(), type.end(), type[0]) == n) {
    fill(ans.begin(), ans.end(), 1);
    print(ans);
    return;
  } else if (n % 2 == 0) {
    for (int i = 0; i < n; i += 1) ans[i] = 1 + i % 2;
    print(ans);
    return;
  } else if (all_distinct()) {
    for (int i = 0; i < n; i += 1) ans[i] = 1 + i % 2;
    ans[0] = 3;
    print(ans);
    return;
  }
  graph.resize(n + 1);
  for (auto &it : graph) it.clear();
  for (int i = 0; i + 1 < n; i += 1) {
    if (type[i] != type[i + 1]) {
      graph[i].push_back(i + 1);
      graph[i + 1].push_back(i);
    }
  }
  if (type[0] != type[n - 1]) {
    graph[0].push_back(n - 1);
    graph[n - 1].push_back(0);
  }
  for (int i = 0; i < n; i += 1) {
    if (vis[i] == 0) {
      dfs(i, -1);
    }
  }
  print(vector<int>(ans.begin(), ans.begin() + n));
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int test = 1;
  cin >> test;
  while (test--) solve();
  return 0;
}
