哎
#include <iostream>
using namespace std;
void main()
{
int number;
cin>>number;
int i;
int flag;
for(i=2;i<number;i++)
{
if(number%i==0)
{
flag=0;
cout<<number<<" is not a prime number"<<endl;
break;
}
}
if(flag)
cout<<number<<" is a prime number"<<endl;
}