[25일차][프로그래머스][86051]없는 숫자 더하기

def solution(numbers):
    check_arr = [idx for idx in range(10)]
    
    for number in numbers:
        index = check_arr.index(number)
        check_arr[index] = 0
        
    return sum(check_arr)

def solution(numbers):
    return 45 - sum(numbers)