meetings = [[1, 4], [3, 5], [0, 6], [5, 7], [3, 8], [5, 9], [6, 10], [8, 11]]

new = []

for start, end in meetings:
    new.append([end, start])

new.sort()

count = 1
end_time = 0

for end, start in new:
    if start >= end_time:
        count += 1
        end_time = end

print(count)