#include<stdio.h>
//#include<conio.h>

int uc(long x)
{ return x%10; }

int main()
{
 //clrscr();
 freopen("koba.in","r",stdin);
 freopen("koba.out","w",stdout);
 long i,t1,t2,t3,t4,s,n;
 scanf("%ld%ld%ld%ld",&n,&t1,&t2,&t3);
 s=uc(t1)+uc(t2)+uc(t3);
 for(i=1; i<=n+160; i++)
 {
  t4=uc(uc(t3)+uc(uc(t2)*uc(t1)));
  s+=t4;
  t3=uc(t4); t2=uc(t3); t1=uc(t2);
 }
 printf("%ld",s);
 return 0;
}