using namespace std;
int main()
{
unsigned n,a,b,s2,s1,d1,d2;
cin>>n;
for (a=1;a<=n;a++)
for (b=1;b<=n;b++)
if(a+b==n)
{
s1=0;
s2=0;
for (d1=1;d1<=a;d1++)
if (a%d1==0)
s1=s1+1;
for (d2=1;d2<=b;d2++)
if (b%d2==0)
s2=s2+1;
if (s1==2 && s2==2)
{
cout< return 0;
}
}
}
