Both are important, but doing the right thing is a prerequisite for doing that particular thing right. If A, B, and C are the keys to success, I may be able to

Both are important, but doing the right thing is a prerequisite for doing that particular thing right. If A, B, and C are the keys to success, I may be able to succeed by doing a mediocre job on A, B, and C, but there's no way I can succeed by not doing A, B, and C, even if I do an excellent job on D, E, and F.