InputDEM = 'C:\Users\xht\Desktop\palaeoice xht\kongur_DEM\kongur_DEM.tif'
  File "<string>", line 1
    InputDEM = 'C:\Users\xht\Desktop\palaeoice xht\kongur_DEM\kongur_DEM.tif'
                                                                             ^
SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in position 2-3: truncated \UXXXXXXXX escape
InputDEM = r'C:\Users\xht\Desktop\palaeoice xht\kongur_DEM\kongur_DEM.tif'
cellsize = arcpy.GetRasterProperties_management(InputDEM,"CELLSIZEX")
cellsize
<Result '30'>
StreamThresholdKM2 = 0.05
TributaryThresholdKM2 = 1
cellsize_int = int(cellsize.getOutput(0))

StreamThreshold = int(float(StreamThresholdKM2) * 1e6 / (cellsize_int * cellsize_int))
TributaryThreshold = int(float(TributaryThresholdKM2) * 1e6 / (cellsize_int * cellsize_int
  File "<string>", line 4
    TributaryThreshold = int(float(TributaryThresholdKM2) * 1e6 / (cellsize_int * cellsize_int
                                                                                              ^
SyntaxError: unexpected EOF while parsing
cellsize_int = int(cellsize.getOutput(0))
StreamThreshold = int(float(StreamThresholdKM2) * 1e6 / (cellsize_int * cellsize_int))
TributaryThreshold = int(float(TributaryThresholdKM2) * 1e6 / (cellsize_int * cellsize_int))
fillDEM =Fill(InputDEM)  ##Fill the sink first
Traceback (most recent call last):
  File "<string>", line 1, in <module>
NameError: name 'Fill' is not defined
fillDEM = arcpy.sa.Fill(InputDEM)  ##Fill the sink first
arcpy.management.GetRasterProperties(fillDEM, "MAXIMUM")
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "C:\Program Files\ArcGIS\Pro\Resources\ArcPy\arcpy\management.py", line 21596, in GetRasterProperties
    raise e
  File "C:\Program Files\ArcGIS\Pro\Resources\ArcPy\arcpy\management.py", line 21593, in GetRasterProperties
    retval = convertArcObjectToPythonObject(gp.GetRasterProperties_management(*gp_fixargs((in_raster, property_type, band_index), True)))
  File "C:\Program Files\ArcGIS\Pro\Resources\ArcPy\arcpy\geoprocessing\_base.py", line 512, in <lambda>
    return lambda *args: val(*gp_fixargs(args, True))
arcgisscripting.ExecuteError: ERROR 001100: Failed because no statistics are available.
Failed to execute (GetRasterProperties).

arcpy.management.CalculateStatistics('fillDEM')
<Result 'fillDEM'>
fill_calculated = arcpy.management.CalculateStatistics('fillDEM')
arcpy.management.GetRasterProperties(fill_calculated, "MAXIMUM")
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "C:\Program Files\ArcGIS\Pro\Resources\ArcPy\arcpy\management.py", line 21596, in GetRasterProperties
    raise e
  File "C:\Program Files\ArcGIS\Pro\Resources\ArcPy\arcpy\management.py", line 21593, in GetRasterProperties
    retval = convertArcObjectToPythonObject(gp.GetRasterProperties_management(*gp_fixargs((in_raster, property_type, band_index), True)))
  File "C:\Program Files\ArcGIS\Pro\Resources\ArcPy\arcpy\geoprocessing\_base.py", line 512, in <lambda>
    return lambda *args: val(*gp_fixargs(args, True))
arcgisscripting.ExecuteError: ERROR 001100: Failed because no statistics are available.
Failed to execute (GetRasterProperties).