diff --git a/Makefile b/Makefile
index a0ad852..dc79962 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 .PHONY: all clean
 
-HTMLS = $(patsubst %.ipynb,html/%.html,$(wildcard *.ipynb))
+HTMLS = $(patsubst notebooks/%.ipynb,html/%.html,$(wildcard notebooks/*.ipynb))
 
 badmathjax = "file:\/\/\/usr\/share\/javascript\/mathjax\/MathJax.js?config=TeX-AMS_CHTML-full,Safe"
 goodmathjax = "https:\/\/cdn.jsdelivr.net\/npm\/mathjax@2\/MathJax.js?config=TeX-AMS_CHTML"
@@ -10,8 +10,8 @@ all: $(HTMLS)
 clean:
 	rm -r html
 
-html/%.html: %.ipynb | html
-	jupyter nbconvert --to html $< --output $@ --execute
+html/%.html: notebooks/%.ipynb | html
+	jupyter nbconvert --to html $< --output $@ --execute --output-dir=.
 	sed -i 's/$(badmathjax)/$(goodmathjax)/' $@
 
 html:
diff --git a/problem0001.ipynb b/notebooks/problem0001.ipynb
similarity index 100%
rename from problem0001.ipynb
rename to notebooks/problem0001.ipynb
diff --git a/problem0002.ipynb b/notebooks/problem0002.ipynb
similarity index 100%
rename from problem0002.ipynb
rename to notebooks/problem0002.ipynb
diff --git a/problem0003.ipynb b/notebooks/problem0003.ipynb
similarity index 100%
rename from problem0003.ipynb
rename to notebooks/problem0003.ipynb
diff --git a/problem0004.ipynb b/notebooks/problem0004.ipynb
similarity index 100%
rename from problem0004.ipynb
rename to notebooks/problem0004.ipynb
diff --git a/problem0005.ipynb b/notebooks/problem0005.ipynb
similarity index 100%
rename from problem0005.ipynb
rename to notebooks/problem0005.ipynb
diff --git a/problem0006.ipynb b/notebooks/problem0006.ipynb
similarity index 100%
rename from problem0006.ipynb
rename to notebooks/problem0006.ipynb
diff --git a/problem0007.ipynb b/notebooks/problem0007.ipynb
similarity index 100%
rename from problem0007.ipynb
rename to notebooks/problem0007.ipynb
diff --git a/problem0008.ipynb b/notebooks/problem0008.ipynb
similarity index 100%
rename from problem0008.ipynb
rename to notebooks/problem0008.ipynb
diff --git a/problem0009.ipynb b/notebooks/problem0009.ipynb
similarity index 100%
rename from problem0009.ipynb
rename to notebooks/problem0009.ipynb
diff --git a/problem0010.ipynb b/notebooks/problem0010.ipynb
similarity index 100%
rename from problem0010.ipynb
rename to notebooks/problem0010.ipynb
diff --git a/problem0011.ipynb b/notebooks/problem0011.ipynb
similarity index 100%
rename from problem0011.ipynb
rename to notebooks/problem0011.ipynb
diff --git a/problem0012.ipynb b/notebooks/problem0012.ipynb
similarity index 100%
rename from problem0012.ipynb
rename to notebooks/problem0012.ipynb
diff --git a/problem0013.ipynb b/notebooks/problem0013.ipynb
similarity index 100%
rename from problem0013.ipynb
rename to notebooks/problem0013.ipynb
diff --git a/problem0014.ipynb b/notebooks/problem0014.ipynb
similarity index 100%
rename from problem0014.ipynb
rename to notebooks/problem0014.ipynb
diff --git a/problem0015.ipynb b/notebooks/problem0015.ipynb
similarity index 100%
rename from problem0015.ipynb
rename to notebooks/problem0015.ipynb
diff --git a/problem0016.ipynb b/notebooks/problem0016.ipynb
similarity index 100%
rename from problem0016.ipynb
rename to notebooks/problem0016.ipynb
diff --git a/problem0017.ipynb b/notebooks/problem0017.ipynb
similarity index 100%
rename from problem0017.ipynb
rename to notebooks/problem0017.ipynb
diff --git a/problem0018.ipynb b/notebooks/problem0018.ipynb
similarity index 100%
rename from problem0018.ipynb
rename to notebooks/problem0018.ipynb
diff --git a/problem0019.ipynb b/notebooks/problem0019.ipynb
similarity index 100%
rename from problem0019.ipynb
rename to notebooks/problem0019.ipynb
diff --git a/problem0020.ipynb b/notebooks/problem0020.ipynb
similarity index 100%
rename from problem0020.ipynb
rename to notebooks/problem0020.ipynb
diff --git a/problem0021.ipynb b/notebooks/problem0021.ipynb
similarity index 100%
rename from problem0021.ipynb
rename to notebooks/problem0021.ipynb
diff --git a/problem0023.ipynb b/notebooks/problem0023.ipynb
similarity index 100%
rename from problem0023.ipynb
rename to notebooks/problem0023.ipynb
diff --git a/problem0025.ipynb b/notebooks/problem0025.ipynb
similarity index 100%
rename from problem0025.ipynb
rename to notebooks/problem0025.ipynb
diff --git a/problem0026.ipynb b/notebooks/problem0026.ipynb
similarity index 100%
rename from problem0026.ipynb
rename to notebooks/problem0026.ipynb
diff --git a/problem0027.ipynb b/notebooks/problem0027.ipynb
similarity index 100%
rename from problem0027.ipynb
rename to notebooks/problem0027.ipynb
diff --git a/problem0028.ipynb b/notebooks/problem0028.ipynb
similarity index 100%
rename from problem0028.ipynb
rename to notebooks/problem0028.ipynb
diff --git a/problem0029.ipynb b/notebooks/problem0029.ipynb
similarity index 100%
rename from problem0029.ipynb
rename to notebooks/problem0029.ipynb
diff --git a/problem0030.ipynb b/notebooks/problem0030.ipynb
similarity index 100%
rename from problem0030.ipynb
rename to notebooks/problem0030.ipynb