bool IsPrine (int val)
{
int i;
or (i = 2;i < val;++i)
{
if (0 == val%i)
break;
}
if (i == val)
return true;
else
return false;
}
int main ()
{
int val;
int i;
scanf ("%d", &val);
if (IsPrine (val))
printf ("Yes!\n");
else
printf ("No!\n");
getch ();
}