Prefix Sum Section

Hey y’all,
it’s been a few days since i started the silver prefix sum section and i’ve been noticing that the problems are hard (for me), i don’t know what’s happening since in my country i literally could participate to the Olympic prospects lessons so i don’t think that i’m dumb, but i don’t know.
So please can y’all let me know if i’m “dumb” or it’s really difficult