Chengdu Shuangliu International Airport is the major international airport serving Chengdu, the capital of Sichuan province, China. It handled 55.9 million passengers in 2019, being among the world's 25 busiest airports in 2019, the fourth-busiest in mainland China, and the busiest in western China.
Ema and her friends are gonna be late for their flight. Now at the beginning of hour

, they are

km away from the airport, and the boarding time is at the beginning of hour

. There are

people in total (Ema herself included), and the

-th one can travel at a speed of

km/h. They will have to reach the airport not later than the boarding time to catch the plane.
However, all is not lost. Ema knows the boarding time will be postponed. The boarding time will be postponed

times: The i-th one will be announced at the beginning of hour

, and postpone the time later to the beginning of hour

. There are still challenges, though, as everyone will only move when he/she can catch the plane in time. That is if the current time before boarding is not enough for him/her to arrive at the airport, he or she will stop moving and just stay at that point; Otherwise, he/she will move on again from where he/she has stopped, or just keep on moving.
Note that every time the boarding time is postponed, everyone will instantly change their action accordingly. Also, everyone only knows the postponement when it is announced, and cannot act on it beforehand.
Please calculate how many people can catch the plane in the end.