#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() 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; }