### solution
print("iris: ", len(set(iris.target)))
print("digits: ", len(set(digits.target)))
print("diabetes: ", len(set(diabetes.target)))
print()

import collections
toCount = [iris.target, digits.target, diabetes.target]
names = ["iris", "digits", "diabetes"]

for i in range(len(toCount)):
  counter=collections.Counter(toCount[i])
  print(names[i], ": ", counter)