num = []
num += gets.split.map &:to_i until num.size == 2
m, n = num
a = gets.split.map(&:to_i)
b = gets.split.map(&:to_i)
max = 0
(0..n-1).each{|j|
	c = 0	
	(0..m-1).each{|i|
		if a[i] == b[j]
			j += 1 
			c += 1
		end
	}
	max = c if c > max
}
p max