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

std::vector<std::string> parse(const char* file)
{
    std::vector<std::string> v;
    if (std::ifstream input{ file }; input.is_open())
    {
        std::string line;
        while (not std::getline(input,line).eof())
        {
            v.push_back(std::move(line));
        }
    }
    return v;
}

int main(int argc, char* argv[])
{
    int answer{};

    auto v = parse(argv[1]);
    for (int c = 0; c < v.size(); ++c)
    {
        int floor = v.size();
        for (int r = 0; r < v.size(); ++r)
        {
            switch (v[r][c])
            {
                case '#':
                    floor = v.size() - r - 1;
                    break;
                case 'O':
                    answer += floor--;
            }
        }
    }
    std::cout << answer << std::endl;
    return 0;
}