#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,b=2; bool f=true; cin>>a; while(b<=a){ if(a%b==0){ f=false; break; } b++; } if(f){ cout<<"Yes"; } else{ cout<<"No"; } return 0; }