import re

def set_battery(bank, joltage, start_pos, end_pos, batteries=2):

    if batteries == 0:
        return 0

    # Get high-low battery, starting from start_pos till end
    for level in range(9,0,-1):
        for pos in range(start_pos, end_pos+1):
            if joltage[pos] != " ":
                # Skip to next if this battery has been set
                continue
            if bank[pos] == str(level):
                joltage[pos] = bank[pos]
                batteries -= 1
                batteries = set_battery(bank, joltage, pos+1, end_pos, batteries)
                if batteries == 0:
                    return 0

    # Nothing changed
    return batteries



def get_joltage(bank):

    joltage = [" "] * len(bank)

    set_battery(bank, joltage, 0, len(bank)-1, 12)

    joltage_str = "".join(joltage)
    joltage_str = re.sub(" ", "", joltage_str)

    return int(joltage_str)



def read_input(filename):
    banks = []
    for bank in open(filename).read().splitlines():
        banks.append(bank)
    return banks


# filename = "day03/my_example_input"
# filename = "day03/example_input" # 3121910778619
filename = "day03/input" # 170147128753455
banks = read_input(filename)


total_joltage = 0
for bank in banks:
    total_joltage += get_joltage(bank)


print(f"Total joltage: {total_joltage}")