def makeArrayConsecutive2(statues):
    return max(statues) - min(statues) - len(statues)
    # return sum([1 for i in range(min(statues), max(statues)) if i not in statues])

print(makeArrayConsecutive2([6, 2, 3, 8]))

'''
Ratiorg got statues of different sizes as a present from CodeMaster 
for his birthday, each statue having an non-negative integer size. 
Since he likes to make things perfect, he wants to arrange them from 
smallest to largest so that each statue will be bigger than the previous 
one exactly by 1. He may need some additional statues to be able to accomplish that. 
Help him figure out the minimum number of additional statues needed.

Example

For statues = [6, 2, 3, 8], the output should be
makeArrayConsecutive2(statues) = 3.

Ratiorg needs statues of sizes 4, 5 and 7.
'''
