For problems which rated above 1900, I can only think about one or two hints of a single problem, so I often have to read the editoral to finish a single problem after one or two hours' time thinking. But I think reading the editoral is useless to improve my CP skill. As you can see, I am a seventh-grader in Ningbo, China and I haven't got much time to practise. How can I get through this situation?