added folder check

app.py

@@ -6,4 +6,10 @@ app = FastAPI()
 
 @app.get("/")
 async def root():
-    return {"message": "Hello World!"}
+    
+    try:
+        file_ls_str = ", ".join(os.listdir("large_files"))
+    except:
+        file_ls_str = "NA"
+    
+    return {"message": f"Hello World! File list: {file_ls_str}"}