{
 Determinati ultima cifra a sumei:
 S = 1^1 + 2^2 + 3^3 + ... + n^n
 n<=500
}

program ultimaCifra;

var
  pc:byte; {penultima cifra a numarului}
  uc:byte; {ultima cifra a numarului}
  rez:byte;
  f:text;

procedure citeste;
begin
  assign(f,'cifra.in');
  reset(f);
  pc:=0;
  read(f,uc);
  while not(eoln(f)) do
  begin
  	pc := uc;
  	read(f,uc);
  end;
  close(f);
end;

procedure afiseaza;
begin
  assign(f,'cifra.out');
  rewrite(f);
  write(f, rez);
  close(f);
end;

function fx(n:integer):integer;
begin
  case n of
   0: fx:=0;
   1: fx:=1;
   2: fx:=5 + (((pc mod 2) * 2) mod 2) * 2;
   3: fx:=2;
   4: fx:=8;
   5: fx:=3;
   6: fx:=9;
   7: fx:=2;
   8: fx:=0;
   9: fx:=9;
  end;
end;

begin
  citeste;
  rez:=(3 * pc + (pc mod 2) * 2 + fx(uc)) mod 10;
  afiseaza;
end.