Minimize the sum of elements in an array

Code_practice.py

'''
The code below is to minimize the sum of all elements in an array. I have provided the time that the code is taking to execute too.
Miniize the sum was the question that was asked in a coding contest that I have recently participated in, and got to know that 
it if a frequently asked question.
'''

import time
# The start time is not that useful in this program. But mentioned just incase
t1 = time.process_time()
a = [20, 7, 5, 4]
for i in range(len(a)-1):
   b = max(a)
   c = b // 2
   a.append(c)
   a.remove(b)
# The below line were written out of for loop only for the purpose to see the sum for every iteration. It can be put inside the
# loop according the user's wish.
final = a
res = reduce(lambda a, b: a + b, final)
print("Min sum " + "-", res)
# End time is important because you should be knowing how long your code is taking to execute
t2 = time.process_time()
# Print start time i.e. even before the actual code starts to executes
print(t1)
# Will print end time
print(t2)