During March 2025, Hyemi developed a C++ Prime Number Checker for the hyemi0622/algorithm repository, focusing on algorithm implementation and problem solving. The solution featured a modular isPrime helper function and a main routine to handle user input and output, resulting in a reusable utility for mathematical validation. Hyemi emphasized clean API design and readable code structure, ensuring the checker could be easily integrated into broader math tooling. While no bugs were addressed during this period, the work demonstrated solid C++ fundamentals, including input parsing and modular function design, and provided a reliable building block for future algorithmic development in C++.