daylast = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
hd = 0
(1..12).each do |i|
    limit = daylast[i - 1]
    (1..limit).each do |x|
        m = x / 10
        l = x % 10
        if i == m + l
            hd += 1
        end
    end
end
puts hd