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