diff --git a/rog/views.py b/rog/views.py
index 69cfe9f..419058e 100644
--- a/rog/views.py
+++ b/rog/views.py
@@ -210,7 +210,7 @@ def ExtentForMainPerf(request):
 @csrf_exempt 
 def ExtentForLocations(request):
     user = request.user
-    grp = user.group.removeprefix('大垣-')
+    grp = user.group[3:-1]
     print(user.group)
     locs = Location.objects.filter(group__contains=grp).aggregate(Extent('geom'), Union('geom'))
     return JsonResponse(locs['geom__extent'], safe=False)