Division Circle. Innopolis

#include <iostream>
#include <cmath>
#include <vector>
#include <queue>
#include <algorithm>
#include <string>
#include <stack>
#include <set>
#define pii pair <int,int>
using namespace std;
using ll = long long;
void cv(vector <int> &v){
    for (auto x: v) cout<<x<<' ';
    cout<<"\n\n";
}

void cvv(vector <vector<int>> &v){
    for (auto x: v){
        for (auto y: x){
            cout<<y<<' ';
        }cout<<'\n';
    }cout<<"\n";
}

void cb(vector <bool> &v){
    for (auto x: v) cout<<x<<' ';
    cout<<"\n\n";
}
vector <vector <int> > gr;

int n;
vector <bool> pr;
vector <int> dv;
bool gd(int a, int b){
    if ( a < b){
        swap(a,b);
    }
    bool r=0;
    //cout<<"(a/b)= "<<a/b<<'\n';
    //cout<<"(a / b) * b == "<<(a / b) * b<<"\n";
    if ( (a / b) * b == a && pr[a/b] == 1){
           // cout<<"good\n";
        r = 1;
    }  else {
        //cout<<"bad\n";
        r = 0;
    }
    return r;
}


bool GD(vector <int> &v){
    int sz = v.size();
    bool r = 1;
    if (!gd(v[0], v[sz-1])) r = 0;
    for (int i = 1; i < sz; ++i){
        if (!gd(v[i], v[i-1])){
            r = 0;
        }
    }
    return r;
}

void god(vector <int> v){
    cout<<"GO\n";
    int sz = v.size();
    cout<<"sz= "<<v.size()<<"\n";
    bool r = 1;
    if (!gd(v[0], v[sz-1])){
        r = 0;
        cout<<"BAD\n";
        cout<<v[0]<< v[sz-1]<<'\n';
    }
    for (int i = 1; i < sz; ++i){
            cout<<"i= "<<i<<"\n";
        if (!gd(v[i], v[i-1])){
                cout<<"BAD\n";
            r = 0;
            cout<<v[i]<< v[i-1]<<'\n';
        }
    }
    cout<<"r= "<<r<<"\n";
}

int main()
{
    cin>>n;
    pr.resize(n+1, 1);
    for (int i=2; i<=n; ++i){
        for (int j = i*2; j <= n; j += i){
            pr[j] = 0;
        }
    }
    for (int i = 1; i <= n;++i){
        if (n % i == 0) dv.push_back(i);
    }
    gr.resize(dv.size());
    //cv(dv);
    for (int i = 0;i<dv.size();++i){
        for (int j = 0; j != i && j < dv.size(); ++j){
               // cout<<"dv: "<<dv[i]<<' '<<dv[j]<<"\n";
            if (gd(dv[i], dv[j])){
                gr[i].push_back(dv[j]);
                gr[j].push_back(dv[i]);
            }
        }
    }
    /*for (int i = 0;i<gr.size();++i){
            cout<<dv[i]<<": ";
        for (auto x: gr[i]) cout<<x<<' ';
        cout<<"\n";
    }*/
    //cout<<"dv: ";
    //cv(dv);
    set <vector <int> > ptn;

    do {
        //cv(dv);
        vector <int> h;
      for (int i = 0; i < dv.size(); ++i){
          h.push_back(dv[i]);
            ptn.insert(h);
      }
  } while ( next_permutation(dv.begin(), dv.end()) );
  //cout<<"ptn\n";
  //for (auto x: ptn) cv(x);
  int mx_sz = 0;
  vector <int> mx_v;
  for (auto x: ptn){
        //cv(x);
  //cout<<GD(x)<<"\n";
    if ( GD(x) ){
            //cout<<"GD\n";
    //cv(x);
        if (x.size() > mx_sz){
              //  cout<<"more\n";
            mx_sz = x.size();
            mx_v = x;
        }
    }
  }
  cout<<mx_sz<<"\n";
  cv(mx_v);
  /*vector <int> l = {1,2,10,5};
  //cout<<GD(l);
  god(l);
  cout<<GD(l);*/
}