n = gets.to_i
s = gets.split.map &:to_i
t = gets.split.map &:to_i
a = Array.new(n) {[nil] * n}

sum = 0
row1 = [false] * n
col1 = [false] * n
row0 = n

s.each_with_index do |x, i|
    if x == 0
        n.times { |j| a[i][j] = 0 }
    elsif x == 2
        sum += n
        row0 -= 1
        row1[i] = true
        n.times do |j|
            col1[j] = true
            a[i][j] = 1
        end
    end
end
t.each_with_index do |x, j|
    if x == 0
        n.times { |i| a[i][j] = 0 }
    elsif x == 2
        sum += row0
        col1[j] = true
        n.times do |i|
            row1[i] = true
            a[i][j] = 1
        end
    end
end
n.times do |i|
    n.times do |j|
        if !a[i][j]
            if !row1[i] or !col1[j]
                row1[i] = col1[j] = true
                a[i][j] = 1
                sum += 1
            end
        end
    end
end

p sum