include <cstdio> #include <algorithm> using namespace std; int top(int n,int cnt) { for(int i=1;i<=n;i++) { if(n%i==0) cnt++; } return cnt; } int main() { int n,cnt; scanf("%d",&n); if(top(n,cnt)==2) { printf("Yes"); } else { printf("No"); } return 0; }