diff --git a/src/components/Operator.vue b/src/components/Operator.vue
index bf4a4ff..c0b8c8a 100644
--- a/src/components/Operator.vue
+++ b/src/components/Operator.vue
@@ -124,7 +124,11 @@ const logVal = ref(1)
 const roomSize = ref(0)
 
 watch(() => {
-  roomSize.value = props.input.match(/\d+/g)[0]
+  if (props.input) {
+    roomSize.value = props.input?.match(/\d+/g)[0]
+  } else {
+    roomSize.value = 0
+  }
 })
 
 const changeLogVal = val => {