func_code_string: #include <bits/stdc++.h>   using namespace std;   signed main() {     ios::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     long long t;     cin >> t;     while (t--) {       long long n, sum = 0;       cin >> n;       vector<long long> v(n), ans, odd;       for (long long i = 0; i < n; i++) {         cin >> v[i];         if (v[i] % 2 == 0) {           ans.push_back(i);         } else           odd.push_back(i);         sum += v[i];       }       long long count = 0;       for (long long i = 2; i * i <= sum; i++) {         if (sum % i == 0) count++;       }       if (count > 0) {         cout << n << endl;         for (long long i = 0; i < n; i++) cout << i + 1 <<    ;       } else {         cout << n - 1 << endl;         odd.pop_back();         for (long long i = 0; i < ans.size(); i++) {           cout << ans[i] + 1 <<    ;         }         for (long long i = 0; i < odd.size(); i++) {           cout << odd[i] + 1 <<    ;         }       }       cout << endl;     }   }   