백준 4821번: 페이지 세기 #Python

import sys

while True:
    total_page = int(sys.stdin.readline())

    if total_page == 0:
        break
    
    print_page_count = [0] * (total_page + 1)
    print_range_list = sys.stdin.readline().rstrip().split(',')

    for print_range in print_range_list:
        
        if '-' in print_range:
            low, high = map(int, print_range.split('-'))

            for i in range(low, high + 1):
                
                if i <= total_page:
                    print_page_count[i] += 1

            continue
        
        page = int(print_range)

        if page <= total_page:
            print_page_count[page] += 1
    
    print(sum([1 if 1 <= i else 0 for i in print_page_count]))