# import NumPy library
import numpy as np

# define your list
my_list = [1, 2, 3, 2, 4, 5, 3, 6]

# find unique items in the list and their counts
unique, counts = np.unique(my_list, return_counts=True)

# filter values whose count is greater than 1
duplicates = unique[counts > 1]

# print the duplicates if present
if len(duplicates) != 0:
    print("Duplicates:", duplicates)
else:
    print('No duplicates found!')