while True:
    n = int(input())
    if n==0:
        break
    s = input().split()
    s1 = []
    for i in range(n):
        a = list(s[i])
        a.sort()
        s1.append("".join(a))

    s2 = []
    for i in range(n):
        if s1.count(s1[i]) == 1:
            s2.append(int(s[i]))

    s2.sort()
    if len(s2) == 0:
        print("None")
    else:
        for nn in s2:
            print(nn,end=" ")
        print()