program sdfgh;
var
f,g:text;
t,i:integer;
x:string[101];
c,j,er,n,s,e:word;
begin
 assign(f,'cifra.in');
 reset(f);
 assign(g,'cifra.out');
 rewrite(g);
 readln(f,t);
 for i:=1 to t do
   begin
     readln(f,x);
     delete(x,1,length(x)-2);
     val(x,c,er);
     s:=0;
     for j:=1 to c do
      begin
      er:=1; e:=2;
      while (e<=j) {and (er>0)} do
       begin
        er:=(er*j) mod 10;
        inc(e);
       end;
      s:=(s+er) mod 10;
     end;
     writeln(g,s);
    end;
    close(f);
    close(g);
  end.