while True:
    s=int(input())
    if s==0:
        break
    li=list(input().split())
    lis=[]
    for i in range(s):
        lia=list(li[i])
        lia.sort()
        lis.append(int("".join(lia)))
    lic=[]
    lid=list(map(int,li))
    for i in range(s):
        if (lis.count(lis[i])==1):
            lic.append(lid[i])
    if len(lic)==0:
       print("None")
    else:
        lic.sort()
        for t in lic:
            print(t,end=" ")