#include <iostream>
#include <bits/stdc++.h>
#include <fstream>
using namespace std;
# define ll long long
//#define int long long
#define forn(i,n) for(int i = 0; i < (int)n; ++i)
const int mod =  998244353;
int mul (int x, int y){
    return (x * y)%mod;
}
int binpow(int x, int y)
{
    int z = 1;
    while(y)
    {
        if(y & 1) z = mul(z, x);
        x = mul(x, x);
        y >>= 1;
    }
    return z;
}
const int N = 200001;
int ff[N];
void beg(){
    ff[0] = 1;
    for(int i = 1; i<N; ++i){
        ff[i] = mul(ff[i - 1], i);
    }
}
int obr(int x)
{
    return binpow(x, mod - 2);
}

int divide(int x, int y)
{
    return mul(x, obr(y));
}
int c(int n, int k){
    return divide(ff[n], mul(ff[k], ff[n-k]));
}

int bsearch(int cur, vector<int>&a, int start, int end){
    while(start +1 < end){
        int mid = (start + end)/2;
        if(a[mid]+a[cur]>0){
            end = mid;
        } else {
            start = mid;
        }
    }
    return end;

}
int nod(int a, int b){
    if(b == 0){
        return a;
    }
    return nod(b, a%b);
}
int nok(int a, int b){
    return a*b/nod(a,b);
}
bool prost(int a){
    for(int i = 2;i<=sqrt(a);++i){
        if(a%i == 0){
            return 1;
        }
    }
    return 0;
}

const int MAXR = 1000005;

ll cubic_root(ll x)
{
    ll l = 0, r = MAXR;
    while (l != r) {
        ll m = (l + r + 1) / 2;
        if (m * m * m > x)
            r = m - 1;
        else
            l = m;
    }
    return l;
}
bool prov(string s){
    for(int i=0;i<s.size()/2;++i){
        if(s[i]!=s[s.size()-1-i]){
            return 0;
        }
    }
    return 1;
}

vector<int> prefix_function (string s) {
    int n = (int) s.length();
    vector<int> pi (n);
    for (int i=1; i<n; ++i) {
        int j = pi[i-1];
        while (j > 0 && s[i] != s[j])
            j = pi[j-1];
        if (s[i] == s[j])  ++j;
        pi[i] = j;
    }
    return pi;
}

signed main(){
    cin.tie(0);
    ios_base::sync_with_stdio(0);
   // std::string name = "/home/rasull/FFCF/equatation.in";
   // fstream input(name, input.in);
    //ifstream in("/home/rasull/FFCF/tree.in");
    //ofstream out("/home/rasull/FFCF/tree.out");
   int t;
   cin >> t;
   forn(_,t){
       int n;
       cin >>n;
       vector<int>a(n);
       forn(i,n){
           cin >> a[i];
       }
       int prost[11]={2,3,5,7,11,13,17,19,23,29,31};
       vector<int>ans(n,-1);
       int col = 0;
       for(int i=0;i<11;++i){
           bool dob=0;
           forn(j,n){
               if(a[j]%prost[i]==0 && ans[j]==-1){
                   dob=1;
                   ans[j]=col+1;
               }
           }
           if(dob){
               ++col;
           }
       }
       cout<<col<<endl;
       forn(i,n){
           cout<<ans[i]<<" ";
       }
       cout<<endl;
   }
}