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similarity index 100%
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diff --git a/inputs/lecture_2.tex b/inputs/lecture_02.tex
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diff --git a/inputs/lecture_3.tex b/inputs/lecture_03.tex
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diff --git a/inputs/lecture_7.tex b/inputs/lecture_07.tex
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diff --git a/inputs/lecture_22.tex b/inputs/lecture_22.tex
index 3cf5b1b..c1620e9 100644
--- a/inputs/lecture_22.tex
+++ b/inputs/lecture_22.tex
@@ -1,5 +1,6 @@
 \lecture{22}{2023-07-04}{Introduction Markov Chains II}
 \section{Markov Chains}
+\todo{Merge this with the end of lecture 21}
 
 \begin{goal}
     We want to start with the basics of the theory of Markov chains.
diff --git a/probability_theory.tex b/probability_theory.tex
index 300a893..8bbbf5b 100644
--- a/probability_theory.tex
+++ b/probability_theory.tex
@@ -23,16 +23,16 @@
 
 \section*{Prerequisites}
 
-\input{inputs/lecture_1.tex}
+\input{inputs/lecture_01.tex}
 \input{inputs/prerequisites.tex}
 
-\input{inputs/lecture_2.tex}
-\input{inputs/lecture_3.tex}
-\input{inputs/lecture_5.tex}
-\input{inputs/lecture_6.tex}
-\input{inputs/lecture_7.tex}
-\input{inputs/lecture_8.tex}
-\input{inputs/lecture_9.tex}
+\input{inputs/lecture_02.tex}
+\input{inputs/lecture_03.tex}
+\input{inputs/lecture_05.tex}
+\input{inputs/lecture_06.tex}
+\input{inputs/lecture_07.tex}
+\input{inputs/lecture_08.tex}
+\input{inputs/lecture_09.tex}
 \input{inputs/lecture_10.tex}
 \input{inputs/lecture_11.tex}
 \input{inputs/lecture_12.tex}