"""

"""

import sys
from sys import stdin

N = stdin.readline()[:-1]

dic16 = {}

for i in range(16):
    alp = "0123456789ABCDEF"
    c = format(i,'b').zfill(4)
    dic16[ alp[i] ] = c

rdic8 = {}
for i in range(8):
    alp = "01234567"
    c = format(i,'b').zfill(3)
    rdic8[c] = alp[i]

S = []
for i in N:
    S.append(dic16[i])

S = "".join(S)
#print (S)
while len(S) % 3 != 0:
    S = "0" + S

#print (S)

T = []
for i in range(0,len(S),3):

    ns = S[i] + S[i+1] + S[i+2]
    T.append( rdic8[ns] )

#print (T)

"""
while T[0] == 0:
    T = T[1:]
"""

ansdic = {}

for i in T:
    if i not in ansdic:
        ansdic[i] = 0
    ansdic[i] += 1

maxi = 0
for i in ansdic:
    maxi = max(maxi,ansdic[i])

ans = []

for i in ansdic:
    if ansdic[i] == maxi:
        ans.append(i)

ans.sort()
print (*ans)