program p12;
var f,g:text;
    j,n,uc,uc1,i,t,c:longint;
begin
assign(f,'cifra.in');reset(f);
assign(g,'cifra.out');rewrite(g);
readln(f,n);
for i:=1 to n do
  begin
  uc1:=0;
  uc:=0;
  readln(f,t);
  for j:=1 to t do
      begin
      c:=j mod 10;
      case c of
       1,6,5:uc:=c;
       4,9:if j mod 2=1 then uc:=c
            else uc:=c*c;
       2,3,7,8: if j mod 4=1 then uc:=c
                else if j mod 4=2 then uc:=c*c
                else if j mod 4=3 then uc:=c*c*c
                else uc:=c*c*c*c;
       end;
       uc1:=(uc1+uc)mod 10;
       end;
       writeln(g,uc1);
  end;
close(g);
close(f);
end.