include<bits/stdc++.h>

using namespace std; int n; bool pdzs(int x){

if(x==1)return 0;
for(int i=2;i*i<=x;i++){
	if(x%i==0)return 0;
}
return 1;

} int main() {

cin>>n;
if(pdzs(n)){
	cout<<"Yes";
}
else
{
	cout<<"No";
}
return 0;

}