diff --git a/.gitmodules b/.gitmodules
index 27501b1..84033e2 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -70,3 +70,11 @@
 	path = examples/cpplint/simple
 	url = ssh://git@focs.ji.sjtu.edu.cn:2222/JOJ/JOJ3-examples.git
 	branch = cpplint/simple
+[submodule "examples/healthcheck/whitelistedchars-invalid"]
+	path = examples/healthcheck/whitelistedchars-invalid
+	url = ssh://git@focs.ji.sjtu.edu.cn:2222/JOJ/JOJ3-examples.git
+	branch = healthcheck/whitelistedchars-invalid
+[submodule "examples/healthcheck/whitelistedchars-success"]
+	path = examples/healthcheck/whitelistedchars-success
+	url = ssh://git@focs.ji.sjtu.edu.cn:2222/JOJ/JOJ3-examples.git
+	branch = healthcheck/whitelistedchars-success
diff --git a/examples/healthcheck/whitelistedchars-invalid b/examples/healthcheck/whitelistedchars-invalid
new file mode 160000
index 0000000..5c56a61
--- /dev/null
+++ b/examples/healthcheck/whitelistedchars-invalid
@@ -0,0 +1 @@
+Subproject commit 5c56a615bd2462829a97b8326b31c64aec08df78
diff --git a/examples/healthcheck/whitelistedchars-success b/examples/healthcheck/whitelistedchars-success
new file mode 160000
index 0000000..bb9bc06
--- /dev/null
+++ b/examples/healthcheck/whitelistedchars-success
@@ -0,0 +1 @@
+Subproject commit bb9bc06fd5753e7338e9b3230b2fc3e3ce971a05