while True:
    try:
        n = int(input())
        if n == 0:
            break
        else:
            a = input().split()
            b=[]
            for ch in a:
                ch = list(ch)
                ch.sort()
                b.append("".join(ch))
            c=[]
            for i in range(n):
                if b.count(b[i]) == 1:
                    c.append(int(a[i]))
            if len(c) == 0:
                print("None")
            else:
                c.sort()
                for j in c:
                    print(j,end=" ")
                print()
    except EOFError:
        break