This USB-OTG thingy, alongside with my keyboard, made me very happy and excited for a past couple of days. Consider buying one of those if you travel a lot and don't want to bring your laptop everywhere. Here, I use my phone + Termux + NeoVim, so I do not need a mouse. I save the code on my phone and submit it through the browser (tho in the future I will probably use something like submitter https://codeforces.me/blog/entry/136604).