def crepes(a): 
    # base case
    if len(a) == 0: 
        return ""
    elif isinstance(a, str):
        return a + " "
    
    # recursive case
    else: 
        return crepes(a[0]) + crepes(a[1:])

while True:
    t = input()
    if t == "":
        break
    isi = " ".join(set(crepes(eval(t)).split()))

    if len(isi) == 0:
        print("kosoong")
    else:
        print(isi)