#include<stdio.h>
int v[1000],s=0,i,j,aux=0,n,S=0,ok=0,q;
int main ()
{
FILE*f=fopen("koba.in","r");
FILE*g=fopen("koba.out","w");

fscanf (f,"%d %d %d %d",&n,&v[1],&v[2],&v[3]);
v[1]=v[1]%10;
v[2]=v[2]%10;
v[3]=v[3]%10;
s=s+v[1]+v[2]+v[3];
for (i=4;i<=n;i++)
    {v[i]=(v[i-1]+v[i-2]*v[i-3])%10;
     s=s+v[i];
     for (j=1;j<i-3;j++)
	  if (v[i-2]==v[j]&&v[i-1]==v[j+1]&&v[i]==v[j+2])
	      {ok=1;break;}
     if (ok==1) break;
    }
if (ok==0) fprintf(g,"%d",s);
else {i-=3;
      for (q=j;q<=i;q++)
	   S=S+v[q];
      i=i-j+1;
      q=(n-j+1)/i;
      S=S*q;
      q=(n-j+1)%i+j-1;
      s=0;
      for (i=1;i<=q;i++)
	  S=S+v[i];
      
      fprintf(g,"%d",S);
     }
fclose(f);
fclose(g);
return 0;
}