Update exercise links

README.md

@@ -60,8 +60,9 @@ My goal is for lectures to be self-contained. The following books contain overla
 |      | Thu | 06.10.2022 | 08:15 | INM202 | Exercises  | [Exercises on lexical analyzers and basics of grammars](exercises/ex2/) |
 | 4    | Mon | 10.10.2022 | 13:15 | INM200 | Lecture 5            | [LL(1) Parsing](https://tube.switch.ch/videos/38dd46b4) |
 |      | Wed | 12.10.2022 | 08:15 | INM202 | [Lexer Lab](labs/lab02/), [Parser Lab](labs/lab03/), [Parser Lab Presentation](https://tube.switch.ch/videos/TUALwnHh6u). See also [Scallion Presentation](https://tube.switch.ch/videos/f18a2692) |
-|      | Thu | 13.10.2022 | 08:15 | INM202 | Exercises  |  |
+|      | Thu | 13.10.2022 | 08:15 | INM202 | Exercises  | [Exercises on LL(1) Parsing](exercises/ex3/) |
 | 5    | Mon | 17.10.2022 | 13:15 | INM200 | Lecture 6            | [CYK Algorithm for Parsing General Context-Free Grammars](https://tube.switch.ch/videos/672add06) and [Chomsky Normal Form Transformation](https://tube.switch.ch/videos/2d3503f4) |
+|      | Thu | 20.10.2022 | 08:15 | INM202 | Exercises  | [Exercises on CYK Parsing](exercises/ex4/) |
 | 6    | Mon | 24.10.2022 | 13:15 | INM200 | Lecture 7            | [Name Analysis](https://tube.switch.ch/videos/a842b90d), [Inductive Relations](https://tube.switch.ch/videos/5d67c147), [Operational Semantics](https://tube.switch.ch/videos/465af7b1) |
 | 7    | Mon | 31.10.2022 | 13:15 | INM200 | Lecture 8            | [Type Rules, Progress, Preservation](https://tube.switch.ch/videos/bdb5c902), [Type Inference](https://tube.switch.ch/videos/14facfc5) |
 | 8    | Mon | 07.11.2022 | 13:15 | INM200 | Lecture 9            | Finish [Type Inference](https://tube.switch.ch/videos/14facfc5) and start code generation |