样例2346错了

#include<bits/stdc++.h>
using namespace std;
int a;
int main(){
	if(!a%105){
		cout <<"3 5 7";
	}else if(!(a%15)){
		cout << "3 5";
	}else if(!(a%21)){
	    cout<<"3 7";
	}else if(!(a%35)){
	    cout<<"5 7";
	}else if(!(a%3==0)){
	    cout<<3;
	}else if(!(a%5)){
	    cout<<5;
	}else if(!(a%7)){
	    cout<<7;
	}else{
	    cout<<'n';
	}
	return 0;
}