while True:
    t=int(input())
    s1=[]
    s2=[]
    s3=[]
    if t==0:
        break
    else:
        s=list(input().split())
        for i in s:
            x=list(i)
            x.sort()
            x="".join(x)
            s1.append(x)
        k=0
        for i in s1:
            if s1.count(i)==1:
                s3.append(s[k])
            k+=1
        if s3==[]:
            print("None")
        else:
            for i in s3:
                s2.append(int(i))
            s2.sort()
            for i in s2[:-1]:
                print(i,end=" ")
            print(s2[-1])