how to find highest number in list without using max function python

1Numbers = [90,78,34,50,100,99]
2higest_number = 0
3for number in Numbers:
4    if number > higest_number:
5        higest_number = number

1mylist = [1, 7, 3, 12, 5]
2
3min_value = min(mylist)
4max_value = max(mylist)
5

1>>> m = max(a)
2>>> [i for i, j in enumerate(a) if j == m]
3[9, 12]
4