diff --git a/adrtlib/demo.py b/adrtlib/demo.py
index d3d5d57..294d283 100755
--- a/adrtlib/demo.py
+++ b/adrtlib/demo.py
@@ -22,7 +22,7 @@
     fht2idt as fht2idt_orig,
     fht2idt_non_rec as fht2idt_non_rec_orig,
 )
-from adrtlib.ref.common import ADRTResult, Image, Sign
+from adrtlib.ref.common import ADRTResult, Image, Sign, OpCount
 from copy import deepcopy
 
 
@@ -72,6 +72,7 @@ def preformat(arr: Array) -> Array:
     if save_input is not None:
         PILImage.fromarray(np.dstack(input_list).astype("u1")).save(save_input)
 
+    print(f"input shape: {arr.shape}")
     return input_list
 
 
@@ -171,7 +172,7 @@ def get_adrt_func_by_name(func_name: str) -> Func:
 def fht2_minimg(img: Image, sign: Sign) -> ADRTResult:
     assert minimg, "proprietary `minimg` module is not available"
     arr = minimg.fromarray(img).fht2(True, sign == sign)
-    return ADRTResult(arr.asarray(order="yx").tolist(), op_count=-1)
+    return ADRTResult(arr.asarray(order="yx").tolist(), op_count=OpCount(-1))
 
 
 if minimg is not None: