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