ATS

import sys
import string
line = "3833###108##333 - 3333"

def isvalid(symb):
    return (symb >= '0' and symb <= '9') or (symb=='#')
def isdigit(symb):
    return (symb >= '0' and symb <= '9')

def double_last_digit(arr):
    if len(arr) > 0:
        return arr[len(arr)-1]


def check(line):
    prev = 'a'
    symb = 0
    arr = []
    length = len(line)
    skip=False
    sharp_skip = False

    j = 0
    for i in range(0, len(line)):
        symb = line[i]
        if not isvalid(line[i]):
            continue
        if symb == prev and (skip == True or sharp_skip == True):
            continue
        else:
            skip = False
            sharp_skip = False
        if symb == prev and sharp_skip == False and isdigit(symb):
            arr.append(symb)
            skip = True
        if symb == prev == '#' and sharp_skip == False:
            double_last_digit(arr)
            sharp_skip=True
        prev = symb
    print(''.join(arr))

check(line)
'''if len(sys.argv) > 1:
    check(sys.argv[1])'''