#include<iostream> using namespace std; int main(){ int n; cin>>n; int i=2; bool flag=false; while(i<n){ if(n%i == 0){ flag = true; break; } i++; } if(n == 1){ cout<<"No"<<endl; }else if(flag){ cout<<"No"<<endl; }else{ cout<<"Yes"<<endl; } return 0; }