def f(d,A):
    if len(A)==1:return A
    i=0
    while 1:
        try:
            if A[i]!=A[i+1]:break
            i+=1
        except:return A
    b=[[] for i in range(27)]
    for x in A:
        try:b[ord(x[d])-96].append(x)
        except:b[0].append(x)
    A=[]
    for x in b:
        if len(x)!=0:
            x=f(d+1,x)
            A+=x
    return A
for s in f(0,[l.rstrip() for l in __import__("sys").stdin][1:]):print(s)