def move_negative_to_end(lst):
j = 0
for i in range(len(lst)):
if lst[i] >= 0:
lst[i], lst[j] = lst[j], lst[i]
j += 1
return lst
lst = [-1, 8, -21, -3, -2, 7, 15, -30, -40, 3, 6, 9]
print(move_negative_to_end(lst))
'''
run:
[8, 7, 15, 3, 6, 9, -21, -30, -40, -3, -2, -1]
'''