program alex;
var f,g:text;
    s:string;
    i,t,n,z,u,r,p,j,nr:longint;
    er:integer;
begin
assign(g,'cifra.out');rewrite(g);
assign(f,'cifra.in');reset(f);
readln(f,t);
nr:=0;
for i:=1 to t do
    begin
    readln(f,s);
    n:=length(s);
    val(s[n],u,er);
    p:=1;
    r:=u mod 4;
    if r=0 then r:=4;
    case u of
    1:nr:=(nr+1)mod 10;
    2:begin
      p:=1;
      for j:=1 to r do
          p:=(p*2)mod 10;
      nr:=(nr+p)mod 10;
      end;
    3:begin
      p:=1;
      for j:=1 to r do
          p:=(p*3)mod 10;
      nr:=(nr+p)mod 10;
      end;
    4:begin
      p:=1;
      for j:=1 to r do
          p:=(p*4)mod 10;
      nr:=(nr+p)mod 10;
      end;
    5:nr:=(nr+5)mod 10;
    6:nr:=(nr+6)mod 10;
    7:begin
      p:=1;
      for j:=1 to r do
          p:=(p*7)mod 10;
      nr:=(nr+p)mod 10;
      end;
    8:begin
      p:=1;
      for j:=1 to r do
          p:=(p*8)mod 10;
      nr:=(nr+p)mod 10;
      end;
    9:if u mod 2=0 then nr:=(nr+1)mod 10
                   else nr:=(nr+9)mod 10;
    end;
    writeln(g,nr);
    end;
close(f);
close(g);
end.