Stuck with using lists to solve task

[Pedroski55]

Maybe like this:

# first servant opens all doors
tstart = ['open' for i in range(0, 100)]
#  all doors are open, second servant closes every second door and so on
def change(num):
    for i in range(num, len(tstart), num + 1):
        if tstart[i] == 'open':
            tstart[i] = 'closed'
        else:
            tstart[i] = 'open'
# all servants except the first servant
for j in range(1, 100):
    change(j)

count = 0
for i in range(0, 100):
    if tstart[i] == 'open':
        count +=1

print(f'Finally, {count} doors are still open. Mean old Sultan! Unhappy Birthday!')    

Not sure if j needs to go up to 99, check that.