file = open('/Users/mastermito/Dev/AdventOfCode/Day1/input.txt', 'r') sum = 0 lines = file.readlines() ranges = lines[0].strip().split(',') for r in ranges: start, end = r.split('-') for num in range(int(start), int(end) + 1): string = str(num) for sublen in range(1, len(string)//2 + 1): if len(string) % sublen != 0: continue match = True for i in range(len(string)): if string[i] != string[i % sublen]: match = False if match: sum += num break print('Sum is: ', sum)