#include <bits/stdc++.h>

using namespace std;

int v[200005];

int main()
{
    int t , n;
    bool ok1;
    int ok2;
    cin >> t;
    while(t--)
    {
        cin >> n;
        cin >> v[1];
        ok1 = true;
        ok2 = 0;
        for(int i = 2; i <= n; ++i)
        {
            cin >> v[i];
            if(v[i] == v[i-1])
                ok2 = i - 1;
            if(v[i] != v[1])
                ok1 = false;
        }
        if(n % 2 == 0)
            ok2= true;
        if(ok1 == true)
            {
                cout << 1 << '\n';
                for(int i = 1; i <= n; ++i)
                {
                    cout << 1 << " ";
                }
                cout << '\n';
            }
        else
        if(ok2 > 0)
            {
                cout << 2 << '\n';
                if(n%2 == 0)
                for(int i = 1; i <= n; ++i)
                    cout << i % 2 + 1 << " ";
                if(n%2 == 1)
                {
                    for(int i = 1; i <= ok2; ++i)
                    cout << i % 2 + 1 << " ";
                    for(int i = ok2 + 1; i <= n; ++i)
                    cout << (2 - i % 2) << " ";
                }
                cout << '\n';
            }
        else
            {
                cout << 3 << '\n';
                for(int i = 1; i < n; ++i)
                    cout << i % 2 + 1    << " ";
                cout << 3 << '\n';
            }
    }

}