题解在此

#include <iostream>
using namespace std;
int main(){
int a;
cin>>a;
if (a%1050){
cout<<"3 5 7";
}else if (a%150){
cout<<"3 5";
}else if (a%350){
cout<<"5 7";
}else if (a%210){
cout<<"3 7";
}else if (a%30&&a%35!=0){
cout<<"3";
}else if (a%50&&a%21!=0){
cout<<"5";
}else if (a%7==0&&a%15!=0){
cout<<"7";
}else{
cout<<"n";
}
return 0;
}