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