I had discussed on that thesis topic with some student before and he already set up his thesis proposal based on that yesterday night after I sent you my mail. I am sorry, but I am afraid the topic is taken by now. We can discuss on other potential topics that interest you. However note that I told all students discussing with me on a thesis topic that I will only supervise if I am convinced the topic is sound and the student has well prepared the thesis proposal. The same accounts for you, I will only sign until 22 if I am convinced by your proposal. Also note that by now I have around 10 Master Theses to supervise so I am already way beyond capacity. We can of course meet to discuss on potential further topics, but if you see any scope for taking one of my colleagues as supervizer you might be better off because due to a smaller number of students to supervise she/he will have much more time available to support you.