#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 a; cin>>a; if(a==1){ cout<<"No"<<endl; return 0; } for(int a1=2;a1<=sqrt(a);a1++){ if(a%a1==0){ cout<<"No"<<endl; return 0; } } cout<<"Yes"<<endl; return 0; }