#include <iostream>
#include <fstream>
#include <vector>

using Schematic = std::vector<std::string>;

bool check(const Schematic& schematic, int x, int y)
{
    return x >= 0 and y >= 0 and x < schematic.size() and y < schematic[x].size()
        and schematic[x][y] != '.' and not std::isdigit(schematic[x][y]);
}

bool check_adj(const Schematic& schematic, int x, int y)
{
    return check(schematic, x - 1, y - 1)
        or check(schematic,     x, y - 1)
        or check(schematic, x + 1, y - 1)
        or check(schematic, x - 1,     y)
        or check(schematic, x + 1,     y);
}

int find_nums(const Schematic& schematic)
{
    int sum{};

    for (int x = 0; x < schematic.size(); ++x)
    {
        const std::string& line = schematic[x];

        int cur{};
        bool adj{ false };

        for (int y = 0; y < line.size(); ++y)
        {
            if (std::isdigit(line[y]))
            {
                cur = 10 * cur + (line[y] - '0');
                adj = adj or check_adj(schematic, x, y);
            }
            else
            {
                if (cur > 0)
                {
                    adj = adj or check(schematic, x - 1, y)
                              or check(schematic, x, y)
                              or check(schematic, x + 1, y);
                    sum += adj ? cur : 0;
                }
                cur = 0;
                adj = false;
            }
        }
    }

    return sum;
}

int main(void)
{
    int answer{};
    Schematic schematic{};

    std::ifstream input{ "resources/input.txt" };
    if (input.is_open())
    {
        std::string line;
        while (not std::getline(input,line).eof())
        {
            line.push_back('.');
            schematic.push_back(std::move(line));
        }
    }
    input.close();

    answer = find_nums(schematic);

    std::cout << answer << std::endl;
    return 0;
}