0.7

string = input().split(" : ")

my_dict = {}

while string[0] != "end":
    course = string[0]
    name = string[1]
    if course not in my_dict:
        my_dict[course] = []
        my_dict[course].append(name)
    else:
        my_dict[course].append(name)
    string = input().split(" : ")

for key, value in sorted(my_dict.items(), key=lambda x: (len(x[1]), x[0]), reverse=True):
    print(f"{key}: {len(value)}")
    for i in value:
        print(f"-- {i}")