Hi all, I'm applying for an REU that requires 3 rec letters. I have 1 strong letter from a professor I worked with for a year, 1 from a prof I get along with really well, and I feel both of those are fairly strong. I've been working with a different professor for about 5 months now. When i asked him for a rec letter he told me if I wrote one, he would sign it. Is this bad or good? I've never written anything like this before. I could get someone else to do it, but I don't feel like they know me well enough. Thoughts?