#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(){ //,从2开始到根号n int n,i=1; bool f=true; cin>>i; while(i<=n/i){ if(n%i==0){ //cout<<"No"; f=false ; break; } i++; } if(f) cout<<"Yes"; else{ cout<<"No"; } return 0; }