It used `a = lst[i]` instead of taking the stride index into account (that is, it should have been `a = lst[i+idx]`). Anyway, the exact same value is in b, so use that instead. Test case by Tapple Gao.
It used `a = lst[i]` instead of taking the stride index into account (that is, it should have been `a = lst[i+idx]`). Anyway, the exact same value is in b, so use that instead. Test case by Tapple Gao.