Update app.py

app.py

@@ -207,11 +207,11 @@ start_node = st.text_input(
     value=str(st.session_state.start_node)
 )
 
-#try:
-#    start_node = int(start_node)
-#except ValueError:
-#    st.error("Please enter a valid numeric content ID.")
-#    st.stop()
+try:
+    start_node = int(start_node)
+except ValueError:
+    st.error("Please enter a valid numeric content ID.")
+    st.stop()
 
 
 # Input: Student ID