#include <iostream>
#include <vector>
#include <set>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <string>
#include <map>
#include <set>
#include <cassert>
#include <ciso646>
#include <climits>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <array>
#include <bitset>
#include <deque>
#include <forward_list>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#include <algorithm>
#include <complex>
#include <functional>
#include <initializer_list>
#include <iterator>
#include <limits>
#include <locale>
#include <numeric>
#include <regex>
#include <string>
#include <utility>
#include <fstream>
#include <iostream>
#include <sstream>
#include <iomanip>
#include <random>
#include <memory>
#include <chrono>
using namespace std;
const int inf = 1e9 + 7;
using ll = long long;
#define pb push_back
#define v vector<ll>
#define sorti sort(s.begin(), s.end());
ll gcd (ll a, ll b) {
    if (b == 0) {
        return a;
    }
    return gcd(b, a % b);
}


int main() {
    ll t = 1;
    cin >> t;
    for (int u = 0; u < t; u++) {
        ll n;
        cin >> n;
        vector<ll> s(n), dp(n, -1);
        for (int i = 0; i < n; i++) {
            cin >> s[i];
        }
        vector<ll> pr(11);
        pr[0] = 2;
        pr[1] = 3;
        pr[2] = 5;
        pr[3] = 7;
        pr[4] = 11;
        pr[5] = 13;
        pr[6] = 17;
        pr[7] = 19;
        pr[8] = 23;
        pr[9] = 29;
        pr[10] = 31;
        ll kol = 1;
        for (int i = 0; i < pr.size(); i++) {
            ll f = 0;
            for (int j = 0; j < n; j++) {
                if (dp[j] == -1 && s[j] % pr[i] == 0) {
                    f++;
                    dp[j] = kol;
                }
            }
            if (f > 0) {
                kol++;
            }
        }
        ll koli = -1;
        for (int i = 0; i < n; i++) {
            koli = max(koli, dp[i]);
        }
        cout << koli << endl;
        for (int i = 0; i < n; i++) {
            cout << dp[i] << " ";
        }
        cout << endl;
    }
    return 0;
}