#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>
#include <string>
#include <cctype>
#include <iterator>

int main(int argc, char* argv[]) {
    if (argc < 3) {
        std::cerr << "Usage: " << argv[0] << " <inputfile> <outputfile>\n";
        return 1;
    }

    // Read file into buffer
    std::ifstream infile(argv[1], std::ios::binary);
    if (!infile) {
        std::cerr << "Error opening input file.\n";
        return 1;
    }
    std::vector<char> buffer((std::istreambuf_iterator<char>(infile)),
                             std::istreambuf_iterator<char>());
    infile.close();

    if (buffer.empty()) {
        std::cerr << "Input file is empty.\n";
        return 1;
    }

    // 1) Remove all ASCII 155 (0x9B)
    buffer.erase(std::remove_if(buffer.begin(), buffer.end(),
                                [](char c){ return static_cast<unsigned char>(c) == 155 || (c) == 62; }),
                 buffer.end());

    // 2) Remove form feed (0x0C) from the last 16 bytes only
    if (!buffer.empty()) {
        size_t start = (buffer.size() > 16) ? buffer.size() - 16 : 0;
        buffer.erase(std::remove(buffer.begin() + start, buffer.end(), (char)12), buffer.end());
    }

    // 3) Remove one space preceding every occurrence of: digit '/' space digit
    //    i.e. remove the single space immediately before the pattern "x/ x" (x = digit)
    std::vector<char> out;
    out.reserve(buffer.size());

    const size_t n = buffer.size();
    for (size_t i = 0; i < n; ++i) {
        // If current char is a space and the next 4 characters exist and match:
        // [digit] '/' ' ' [digit] starting at i+1  -> remove this current space (skip it)
        if (buffer[i] == ' ' && i + 4 < n &&
            std::isdigit(static_cast<unsigned char>(buffer[i + 1])) &&
            buffer[i + 2] == '/' &&
            buffer[i + 3] == ' ' &&
            std::isdigit(static_cast<unsigned char>(buffer[i + 4]))) {
            // skip this single space (do not push it to out)
            continue;
        }

        // Otherwise, keep the character
        out.push_back(buffer[i]);
    }

    // 4) Write output
    std::ofstream outfile(argv[2], std::ios::binary);
    if (!outfile) {
        std::cerr << "Error opening output file.\n";
        return 1;
    }
    if (!out.empty()) {
        outfile.write(out.data(), out.size());
    }
    outfile.close();

    return 0;
}