fix clear bug

app.py

@@ -752,10 +752,9 @@ def update_example_problem():
 
 
 def clear():
-    problem_example_text, _ = get_random_problem()
+    problem_example_text = get_random_problem()
     return "", 0.1, "", problem_example_text, problem_example_text
 
-
 with gr.Blocks(css=css, title="Math Olympiad Solver") as demo:
     running_done = False
     btn_list = []