diff --git a/28/25.txt b/28/25.txt
new file mode 100644
index 0000000..60a89ed
--- /dev/null
+++ b/28/25.txt
@@ -0,0 +1 @@
+O
\ No newline at end of file
diff --git a/manifest.json b/manifest.json
index 2d4348d..7eb50dc 100644
--- a/manifest.json
+++ b/manifest.json
@@ -193,6 +193,7 @@
 		"28-13",
 		"28-15",
 		"28-17",
+		"28-21",
 		"29-title",
 		"29-01",
 		"29-03",