from math import factorial def list_1(): cnt = 0 my_dict = {} my_list = list(map(int, input().split())) for i in my_list: if i not in my_dict.keys(): my_dict.update({i:1}) else: my_dict.update({i: my_dict.get(i) + 1}) for i in my_dict.values(): if i >= 3: cnt += int(factorial(i)/(2*factorial(i - 2))) elif i == 2: cnt += 1 print(my_list) print(my_dict) print("counter:", cnt) list_1()