diff --git a/src/scgenerator/initialize.py b/src/scgenerator/initialize.py
index 558cbaf..5bf9ff0 100644
--- a/src/scgenerator/initialize.py
+++ b/src/scgenerator/initialize.py
@@ -526,7 +526,7 @@ def validate_config_sequence(*configs: os.PathLike) -> Tuple[Config, int]:
         previous = Config.from_bare(override_config(dico, previous))
         variables |= {(k, tuple(v)) for k, v in previous.variable.items()}
         variables.add(("repeat", range(previous.repeat)))
-    return previous, int(np.product([len(v) for k, v in variables if len(v) > 0]))
+    return previous, int(np.product([len(v) for _, v in variables if len(v) > 0]))
 
 
 def wspace(t, t_num=0):
diff --git a/src/scgenerator/utils/__init__.py b/src/scgenerator/utils/__init__.py
index 9a2b1e0..2fb428b 100644
--- a/src/scgenerator/utils/__init__.py
+++ b/src/scgenerator/utils/__init__.py
@@ -196,7 +196,7 @@ def format_variable_list(l: List[Tuple[str, Any]]):
 
 
 def branch_id(branch: Tuple[Path, ...]) -> str:
-    return "".join("".join(re.sub(r"id\d\S*num\d", "", b.name).split()[2:-2]) for b in branch)
+    return "".join("".join(re.sub(r"id\d+\S*num\d+", "", b.name).split()[2:-2]) for b in branch)
 
 
 def format_value(value) -> str: