Multithreaded Diagonal Sums in C

I am looking for an experienced C programmer to develop a multithreaded algorithm for calculating diagonal sums. This will involve taking a two-dimensional array as input and computing the sum from the main diagonal and from the secondary diagonal and returning that result. The execution should be multithreaded in order to improve the performance and speed of the calculation. Ideally, the programmer should have a deep understanding of C programming and experience working with multithreaded programs. Please message me for further analysis.