#include<bits/stdc++.h>
using namespace std;
const int maxval{300000};
int main(){
int n;
cin>>n;

vector<int>inp(n+1);
for (int i = 1; i <= n; i++)
{
    cin>>inp[i];
}
int a,b;
cin>>a>>b;


vector<vector<int>>v(n+maxval+1);
for (int i = 1; i <= n; i++)
{
    int x=inp[i];;
    
    for (int j = 2; j*j<= x; j++)
    {
        if(x%j)continue;
         while((x%j)==0)x/=j;  
         v[i].push_back(n+j), v[n+j].push_back(i);
  }
if(x>1){
     v[i].push_back(x+n);
          v[x+n].push_back(i);

}
    
}
bool found=false;
vector<int>par(n+maxval+1,-1);
vector<int>vis(n+maxval+1);
queue<int>q;
q.push(a);
while (!q.empty())
{

    int node=q.front();
    q.pop();
    if(node==b){found=true;break;}
      vis[node]=true;
    for(auto x:v[node]){
        if(par[x]!=-1)continue;
        if(vis[x]==false){
         par[x]=node;
      q.push(x);
        }
    }
}


if(found){
vector<int>ans;

for (int i = b; i !=a&&par[i]!=-1; i=par[par[i]])
{ 
    ans.push_back(i);
}

cout<<ans.size()+1<<"\n";
reverse(ans.begin(),ans.end());
cout<<a<<" ";
for (int i = 0; i < ans.size(); i++)
{
        cout<<ans[i]<<" "; 
}
cout<<"\n";

}
else{
    cout<<-1<<"\n";
}
    return 0;
}