#include <iostream>
using namespace std;
bool KTSNT(int x)
{
if(x<2)
return false
; for(int i=2; i<=x/2; i++)
if(x%i==0)
return false;
return true;
}
void main()
{
unsigned int n;
cout<<"Nhap vao so nguyen duong n: ";
cin>>n;
if(KTSNT(n)==true)
cout<< n << " la so nguyen to!";
else
cout<< n <<" khong la so nguyen to!";
cout<<endl;
}