I've solved 9 problems from atcoder dp contest but still I can't even solve basic knapsack problems on my own. I will be really thankful if someone can tell me about any resource from where I can practice dp right from basic to medium difficulty.

Another thing to mention, Most of easy dp problems (1000 +- 200) on codeforces are solvable with other things so I will be very thankful if some problems are told or any resource is told where there is only dp.

Thanks in advance