解题思路：考察对贪心、排序、队列理解和运用。 

def max_tasks(n, tasks):
    tasks.sort(key=lambda x: x[1])  
    count = 0
    end_time = -1
    for task in tasks:
        if task[0] >= end_time:  
            count += 1
            end_time = task[1]  
    return count
 
 
n = 3
tasks = [
    [1, 1],
    [1, 2],
    [1, 3]
]
 
 
print(max_tasks(n, tasks))