#include <bits/stdc++.h>
using namespace std;
bool cmp(pair<long long int, long long int> a,
         pair<long long int, long long int> b) {
  return a.first < b.first;
}
bool check(int a) {
  int sum = 0;
  while (a > 0) {
    sum += (a % 10);
    a /= 10;
  }
  if (sum == 10) return true;
  return false;
}
bool prime[10005];
void seivertexe() {
  memset(prime, 1, sizeof(prime));
  prime[0] = 0;
  prime[1] = 0;
  for (long long int i = 2; i <= 10000; i++) {
    if (prime[i] == 1) {
      for (long long int j = i * i; j <= 10000; j += i) prime[j] = 0;
    }
  }
}
template <typename T>
std::string NumberToString(T Number) {
  std::ostringstream ss;
  ss << Number;
  return ss.str();
}
bool isPrime(long long int n) {
  if (n <= 1) return false;
  if (n <= 3) return true;
  if (n % 2 == 0 || n % 3 == 0) return false;
  for (long long int i = 5; i * i <= n; i = i + 6)
    if (n % i == 0 || n % (i + 2) == 0) return false;
  return true;
}
long long int power(long long int x, long long int y) {
  if (y == 0)
    return 1;
  else if (y % 2 == 0)
    return (power(x, y / 2) % 1000000007 * power(x, y / 2) % 1000000007) %
           1000000007;
  else
    return (x % 1000000007 *
            (power(x, y / 2) % 1000000007 * power(x, y / 2) % 1000000007) %
            1000000007) %
           1000000007;
}
long long int factorial1(long long int n) {
  return (n == 1 || n == 0)
             ? 1
             : (n % 1000000007 * factorial1(n - 1) % 1000000007) % 1000000007;
}
long long int fact(long long int n) {
  long long int res = 1;
  for (int i = 2; i <= n; i++) res = (res * i) % 1000000007;
  return res % 1000000007;
}
long long int nCr(long long int n, long long int r) {
  return fact(n) % 1000000007 /
         ((fact(r) % 1000000007 * fact(n - r) % 1000000007)) % 1000000007;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  ;
  long long int t;
  cin >> t;
  while (t--) {
    long long int n;
    cin >> n;
    long long int arr[n + 5];
    set<long long int> second;
    for (long long int i = 1; i <= n; i++) {
      cin >> arr[i];
      second.insert(arr[i]);
    }
    if (second.size() == 1) {
      cout << second.size() << "\n";
      for (long long int i = 1; i <= n; i++) {
        cout << 1 << " ";
      }
      cout << "\n";
    } else {
      long long int color[n + 10];
      for (long long int i = 1; i <= n; i++) {
        if (i % 2 == 1) {
          color[i] = 1;
        } else {
          color[i] = 2;
        }
      }
      if (n % 2 == 0 || arr[1] == arr[n]) {
        cout << 2 << "\n";
        for (int i = 1; i <= n; i++) {
          cout << color[i] << " ";
        }
        cout << "\n";
      } else {
        if (arr[1] == arr[n]) {
          cout << 2 << "\n";
          for (int i = 1; i <= n; i++) {
            cout << color[i] << " ";
          }
          cout << "\n";
        } else {
          for (int i = n; i >= 1; i--) {
            if (color[i] == 1)
              color[i] = 2;
            else
              color[i] = 1;
            if (arr[i] == arr[i - 1]) {
              break;
            }
          }
          if (color[1] == color[n]) {
            color[1] = 3;
            cout << 3 << "\n";
            for (int i = 1; i <= n; i++) {
              cout << color[i] << " ";
            }
            cout << "\n";
          } else {
            cout << 2 << "\n";
            for (int i = 1; i <= n; i++) {
              cout << color[i] << " ";
            }
            cout << "\n";
          }
        }
      }
    }
  }
  return 0;
}
