T = gets.to_i
T.times do
    s = gets.chomp.split(//).map(&:to_i)
    while s.length > 1 do
        nS = Array.new
        k = s.length
        for i in 0..k-2
            num = s[i]+s[i+1]
            if num >= 10 then
                num = num/10 + num%10
            end
            nS.push(num)
        end
        s = nS
    end
    p s[0]
end