不难

#include<bits/stdc++.h>
using namespace std;
int main()
{
	int a;
	cin>>a;
	if(a%3==0 and a%5==0 and a%7==0)
	{
		cout<<"3 5 7";
	}
	else if(a%3==0 and a%5==0)
	{
		cout<<"3 5";
	}
	else if(a%3==0 and a%7==0)
	{
		cout<<"3 7";
	}
	else if(a%5==0 and a%7==0)
	{
		cout<<"5 7";
	}
	else if(a%3==0)
	{
		cout<<"3";
	}
	else if(a%5==0)
	{
		cout<<"5";
	}
	else if(a%7==0)
	{
		cout<<"7";
	}
	else if(a%3!=0 or a%5!=0 or a%7!=0)
	{
		cout<<'n';
	}
}