gets.to_i.times{
  s=gets.chomp.chars.map{|c|c.ord-48}
  n=s.size
  n.downto(2){|k|
    0.upto(k-2){|i|
      s[i]+=s[i+1]
      s[i]>9&&s[i]-=9
    }
  }
  p s[0]
}