#include <stdio.h>

FILE *f=fopen("koba.in","r");
FILE *g=fopen("koba.out","w");

int n,t1,t2,t3,t,i,s;
void citire()
{
	fscanf(f,"%d%d%d%d",&n,&t1,&t2,&t3);
	t1%=10;
	t2%=10;
	t3%=10;
}

int main()
{
	citire();

	s=t1+t2+t3;
	for(i=4;i<=n;i++)
	{
		t=(t1*t2+t3)%10;
		t1=t2;
		t2=t3;
		t3=t;
		s+=t;
	}
	
	fprintf(g,"%d",s);

	return 0;
}