// koba.cpp : Defines the entry point for the console application.
//

#include <stdio.h>

int main()
{
	int t,i;
	int a,b,c,e,n;
	FILE *f1,*f2;
	f1=fopen("koba.in","r");
	f2=fopen("koba.out","w");
	fscanf(f1,"%d %d %d %d",&n,&c,&b,&a);
	a=a%10;
	b=b%10;
	c=c%10;
	t=a+b+c;
	for(i=4;i<=n;i++)
	{
		e=a;
		a=(a+b*c)%10;
		c=b;
		b=e;
		t=t+a;
	}
	fprintf(f2,"%d",t);
	fclose(f1);
	fclose(f2);

	return 0;
}