correct cv4

cv4/a_train.c

@@ -76,6 +76,27 @@ struct car* clear_train(struct car* first, const char* target)
         }
     }
     struct car* prev = first;
+
+    if(prev->next->next == NULL)
+    {
+        if(!strcmp(prev->value, target))
+        {
+            struct car* second = prev->next;
+            free(prev);
+            first = second;
+            return first;
+        }
+        else if(!strcmp(prev->next->value, target))
+        {
+            free(prev->next);
+            return first;
+        }
+        else
+        {
+            return first;
+        }
+    }
+
     while (prev->next->next != NULL)
     {
         if(strcmp(prev->value, target))