#include <bits/stdc++.h>
using namespace std;
int main() {
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    vector<int> v(n);
    vector<int> ans(n);
    for (int i = 0; i < n; i++) cin >> v[i];
    int flagie = 1;
    for (int i = 1; i < n; i++)
      if (v[i] != v[i - 1]) flagie = 0;
    if (flagie == 1) {
      cout << 1 << endl;
      for (auto x : ans) cout << 1 << " ";
      cout << endl;
    } else {
      if (n % 2 == 0) {
        ans[0] = 1;
        for (int i = 1; i < n; i++) {
          ans[i] = 3 - ans[i - 1];
        }
        cout << 2 << endl;
        for (auto x : ans) cout << x << " ";
        cout << endl;
      } else {
        if (v[0] == v[n - 1]) {
          cout << 2 << endl;
          ans[0] = 1;
          for (int i = 1; i < n; i++) {
            ans[i] = 3 - ans[i - 1];
          }
          for (auto x : ans) cout << x << " ";
          cout << endl;
        } else {
          int i;
          for (i = 0; i < n - 1; i++) {
            if (v[i] == v[i + 1]) break;
          }
          if (i == n - 1) {
            ans[0] = 1;
            for (int i = 1; i < n; i++) {
              ans[i] = 3 - ans[i - 1];
            }
            ans[n - 1] = 3;
            cout << 3 << endl;
            for (auto x : ans) cout << x << " ";
            cout << endl;
          } else {
            int flag = 1;
            ans[0] = 1;
            for (int i = 1; i < n; i++) {
              if (v[i] == v[i - 1] && flag == 1) {
                ans[i] = ans[i - 1];
                flag = 0;
              } else {
                ans[i] = 3 - ans[i - 1];
              }
            }
            cout << 2 << endl;
            for (auto x : ans) cout << x << " ";
            cout << endl;
          }
        }
      }
    }
  }
}
