type vector=array[1..100] of byte;
const c:vector=(1,4,7,6,5,6,3,6,9,0,1,6,3,6,5,6,7,4,9,0,1,4,7,6,5,6,3,6,9,0,1,6,3,6,5,6,7,4,9,0,
1,4,7,6,5,6,3,6,9,0,1,6,3,6,5,6,7,4,9,0,1,4,7,6,5,6,3,6,9,0,1,6,3,6,5,6,7,4,9,0,1,4,7,6,5,6,3,6,9,0,1,6,3,6,5,6,7,4,9,0);
var f,g:text;
    s,nr:string;
    suma,t,i,cod,nu:integer;
    l:byte;
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,s);
     suma:=0;
     l:=length(s);
     nr:=copy(s,l-2,2);
     val(nr,nu,cod);
     if cod=0
     {transf cu succes}
       then
          begin
           if nu>80 then nu:=nu-80
           else if nu>60 then nu:=nu-60
                else if nu>40 then nu:=nu-40
                     else if nu>20 then nu:=nu-20;
           for i:=1 to nu do
              suma:=suma+c[i];
           writeln(g,suma mod 10);
         end;
    end;
    close(f);
    close(g);
end.