Alternative for using more nested "'IF"functions

I have a matrix measuring the likelihood of a risk occurring and the likely impact. The Ranking are "Low", "Medium" and "High". I can't find figure out the formula that can comprehensively capture it in excel so that when I input the rankings of the two variable, the final ranking will be generated automatically. I have tried to use the IF(AND..... function but it can't capture the whole matrix. I have attached the template i am designing

I Will appreciate your help