Instructions to compile and run:

1. Compile main.cpp with any C++ compiler. Make sure you are using the C++20 standard. Link all header and cpp files in your compiler configuration. No external libraries are required.
2. The program is a command-line exe. Ensure "transactions.json" and "accounts.json" are in the same directory as the .exe file.
3. The program will write both to stdout and to output.txt.
4. This program will ONLY run on Linux.