#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; cin>>n; int i=2; bool f=0; while(i*i<=n){//i<=sprt(n) if(n%i==0) {f=1;break;} i++; } if(f==0){ cout<<"Yes"<<endl; } else{ cout<<"No"<<endl; } return 0; }