题解

#include<iostream>
#include<cmath>
using namespace std;
long long n;
int main(){
    cin>>n;
    if(n<=1){
        cout<<"No";
    }
    else if(n==2){
        cout<<"Yes";
    }
    else if(n%2==0){
        cout<<"No";
    }
    else{
        for(int i=3;i<=sqrt(n);i++){
            if(n%i==0){
                cout<<"No";
                return 0;
            }
        }
        cout<<"Yes";
    }
}