# include <fstream>
using namespace std;

int main ()
{
	ifstream fin ("koba.in");
	ofstream fout ("koba.out");
	int n, t1, t2, t3, s, t;
	fin>>n>>t1>>t2>>t3;
	s=t1%10+t2%10+t3%10;
	
	for (int i=4;i<=n;i++)
	{
		t=t3+t2*t1;		
		t1=t2;t2=t3;t3=t%10;
		s+=t3;
	}
	fout<<s;
	return 0;
}