def find_one(number):
    count = 0
    for i in range(1, number+1):
        string_number = str(i)
        for letter in string_number:
            if int(letter) == 1:
                count += 1
    return count


def main():
    n = 1
    while True:
        result = find_one(n)
        if n % 500 == 0:  # used to monitor progress
            print('At number {}, result {}'.format(n, result))
        if result == n and n != 1:
            break
        else:
            n += 1
    print('The answer is {}'.format(n))

main()