diff --git a/examples2/rte/gen_rte9.py b/examples2/rte/gen_rte9.py
index a7c667dd24dfffb2ec16d3dfbb2c53d2d8e1b408..e1e2f209b325f2470afd6dcf21aa9e870a4faa36 100755
--- a/examples2/rte/gen_rte9.py
+++ b/examples2/rte/gen_rte9.py
@@ -9,7 +9,7 @@ def p(c):
 
 
 def S(depth):
-    if random.randint(0,1) == 0:
+    if depth > MAXD or random.randint(0,1) == 0:
         p('b ')
     else:
         S(depth + 1)
@@ -21,4 +21,3 @@ if __name__ == '__main__':
     S(1)
     p('#$')
     p("\"")
-