program koba;
{$APPTYPE CONSOLE}  
uses  
  SysUtils;   
  
var i,j,n,m:integer;   
    rez,t1,t2,t3,t4,a1,a2,a3,a4:Int64;   
    fin,fout:text;   
{*----------------------------------*}  
begin  
        assign(fin,'koba.in'); reset(fin);
        assign(fout,'koba.out'); rewrite(fout);   
  
        read(fin,n,t1,t2,t3);   
        //T1:=T1 mod 10; T2:=T2 mod 10; T3:=T3 mod 10;   
  rez:=0;
        for i:=1 to n do  
        begin  
                t4:=t3+t2*t1;   
                t4:=t4 mod 10;   
  
                a1:=t2;   
                a2:=t3;   
                a3:=t4;   
                t3:=a3;   
                t2:=a2;   
                t1:=a1;   
  
                rez:=rez+t4;   
  
        end;   
  
        Writeln(fout,rez);   
  
        close(fin);   
        close(fout);   
end.