#include <bits/stdc++.h>   using namespace std;   using ll = long long;   ll min(ll a, ll b) {     if (a < b) return a;     return b;   }   void solve() {     ll testCases;     cin >> testCases;     while (testCases--) {       ll n;       cin >> n;       vector<ll> arr(n);       vector<ll> res(n, 1);       for (int i = 0; i < n; i++) cin >> arr[i];       int i = 0;       for (i = 0; i < n; i++) {         if (arr[i] != arr[(i + 1) % n]) break;       }       if (i == n) {         cout <<  1 n ;         for (i = 0; i < n; i++) cout << 1 <<    ;         cout <<   n ;         continue;       }       if (n % 2 == 0) {         cout <<  2 n ;         for (i = 0; i < n; i++) cout << (i % 2) + 1 <<    ;         cout <<   n ;         continue;       } else {         bool isTwo = 0;         for (i = 0; i < n; i++) {           if (arr[i] == arr[(i + 1) % n]) {             for (int j = 0, k = i + 1; k < n; k++, j ^= 1) res[k] = j + 1;             for (int j = 0, k = i; k >= 0; k--, j ^= 1) res[k] = j + 1;             cout <<  2 n ;             for (auto e : res) cout << e <<    ;             cout <<   n ;             isTwo = 1;             break;           }         }         if (!isTwo) {           cout <<  3 n ;           for (i = 0; i < n - 1; i++) cout << i % 2 + 1 <<    ;           cout <<  3 n ;         }       }     }   }   int main() {     {       ios_base::sync_with_stdio(false);       cin.tie(NULL);     };     solve();     return 0;   }   