1 files changed, 4 insertions, 4 deletions
diff --git a/prolog/problems/world_data/people_in_capitals_1/common.py b/prolog/problems/world_data/people_in_capitals_1/common.py
index b38a96f..cda2e06 100644
--- a/prolog/problems/world_data/people_in_capitals_1/common.py
+++ b/prolog/problems/world_data/people_in_capitals_1/common.py
@@ -13,17 +13,17 @@ facts = 'mondial'
 solution = '''\
 people_in_capitals(N) :-
     findall(Pop,
-        (country(_,_,Capital,_,_,_),
-         city(Capital,_,_,Pop,_,_,_),
+        (country(_,ID,Capital,_,_,_),
+         city(Capital,ID,_,Pop,_,_,_),
          number(Pop)), L),
-    sum(L, N).
+    sum_list(L, N).
 '''
 
 hint_type = {
 }
 
 test_cases = [
-    ('people_in_capitals(N)', [{'N': '316277426'}]),
+    ('people_in_capitals(N)', [{'N': '313163317'}]),        # old solution without equal IDs [{'N': '316277426'}]
 ]
 
 def test(code, aux_code):