a = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
count = 0
12.times do |x|
    y = 1
    while y <= a[x] do
        d = y / 10 + y % 10
        if (x + 1) == d
            count += 1
        end
        y += 1
    end
end
puts count