l = 0
r = len(n) - 1
hash = {}
res_list = []
while r >= l:
# print(n[r])
if n[r] not in hash:
hash[n[r]] = r
res_list.append(n[r])
r -= 1
res = "".join(res_list)
print(res)
l = 0
r = len(n) - 1
hash = {}
res_list = []
while r >= l:
# print(n[r])
if n[r] not in hash:
hash[n[r]] = r
res_list.append(n[r])
r -= 1
res = "".join(res_list)
print(res)