#include <fstream>
#include <iostream>

int main()
{
	std::ifstream file("input.txt");

	long long int joltage_sum = 0;
	const int digit_count = 2; // Use 12 for part 2

	std::string bank;
	while (getline(file, bank)) {
		int indices[digit_count];

		for (int digit_index = 0; digit_index < digit_count; digit_index++) {
			for (int i = 9; i > 0; i--) {
				char digit = i + 48;

				// Start from previous index
				int start_pos = digit_index == 0 ? 0 : indices[digit_index - 1] + 1;

				int index = bank.find(digit, start_pos);

				if (index < bank.size() - digit_count + digit_index + 1 && index != std::string::npos) {
					indices[digit_index] = index;
					break;
				}
			}
		}

		// Collect characters into a single number
		std::string joltage_str;
		for (int index : indices) {
			joltage_str += bank[index];
		}
		long long int joltage = std::stoll(joltage_str);

		std::cout << joltage << std::endl;

		joltage_sum += joltage;
	}

	std::cout << "\nSum: " << joltage_sum << std::endl;
}