var m,n,i:integer;
    f,g:text;
    c,c1:char;
    s:string;
begin
assign(f,'cifra.in');
assign(g,'cifra.out');
reset(f);
rewrite(g);
readln(f,n);
for i:=1 to n do
 begin
  readln(f,s);
  s:='0'+s;
  c1:=s[length(s)-1];
  c:=s[length(s)];
  case c1 of
                           '1':m:=7;
                           '2':m:=4;
                           '3':m:=1;
                           '4':m:=8;
                           '5':m:=5;
                           '6':m:=2;
                           '7':m:=9;
                           '8':m:=6;
                           '9':m:=3;
                           end;
  if ord(c1)mod 2=0 then case c of
                           '1':m:=m+1;
                           '2':m:=m+5;
                           '3','7':m:=m+2;
                           '4','8':m:=m+8;
                           '5':m:=m+3;
                           '6':m:=m+9;
                           '9':m:=m+7;
                           end
  else                   case c of
                           '1','5':m:=m+1;
                           '2','6','9':m:=m+7;
                           '4':m:=m+6;
                           '7':m:=m+4;
                           '8':m:=m+8;
                           end;
   writeln(g, m mod 10);
  end;
 close(f);
 close(g);
end.