course_info = input()

courses = {}

while course_info != "end":
    course, student = course_info.split(" : ")
    if course not in courses:
        courses[course] = [student]
    else:
        courses[course].append(student)

    course_info = input()

sorted_courses = dict(sorted(courses.items(), key=lambda x: -len(x[1])))

for course, student in sorted_courses.items():
    print(f"{course}: {len(student)}")
    for el in sorted(student):
        print(f"-- {el}")