8. Company Users

data = {}

while True:
    register = input()
    if register == 'End':
        break
    register = register.split(' -> ')
    company = register[0]
    employee_id = register[1]
    if company not in data: data[company] = [employee_id]
    else:
        if employee_id not in data[company]:
            data[company].append(employee_id)

order = sorted(data, key=lambda x: x)

for i in order:
    print(i)
    [print(f'-- {x}') for x in data[i]]