def process(s)
  s = s.chars.map(&:to_i)
  while s.size > 1
    s = s.each_cons(2).map{|a,b| a + b >= 10 ? a + b - 9 : a + b }
  end
  s[0]
end
T = gets.to_i
puts T.times.map{ process(gets.chomp) }