新手刷题

#include<bits/stdc++.h>
using namespace std;
int main()
{
    int n;
    cin>>n;
    int flag = 0;
    for(int i = 2;i<n;i++)
    {
        if(n%i == 0)
        {
            flag = 1;
        }
    }
    if(flag == 1 || n == 1)
    {
        cout<<"No";
    }
    else
    {
        cout<<"Yes";
    }
    return 0;
}