program cifre;
var f,g:text;
    t,i:word;
    a:string;
    c:0..9;
function suma(a:string):byte;
var s:0..9;
    n:byte;
begin
     n:=length(a);
     s:=0;
     if n<>1 then
     s:=((ord(a[n-1])-ord('0'))*9) mod 10;
     case a[n] of
     '1':s:=(s+1)mod 10;
     '2':s:=(s+5)mod 10;
     '3':s:=(s+2)mod 10;
     '4':s:=(s+8)mod 10;
     '5':s:=(s+3)mod 10;
     '6':s:=(s+9)mod 10;
     '7':s:=(s+6)mod 10;
     '9':s:=(s+9)mod 10;
     end;
     suma:=s;
end;
begin
     assign(f,'cifra.in');
     assign(g,'cifra.out');
     reset(f);
     rewrite(g);
     readln(f,t);
     for i:=1 to t do begin
         readln(f,a);
         c:=suma(a);
         writeln(g,c);
     end;
     close(f);
     close(g);
end.