def tm009():
#读取输入
s=input()
s=s[::-1]
s2=''
#去重
for i in s:
if i in s2:
continue
s2=s2+i
print(s2)
if __name__ == '__main__':
tm009()
#读取输入
s=input()
s=s[::-1]
s2=''
#去重
for i in s:
if i in s2:
continue
s2=s2+i
print(s2)
if __name__ == '__main__':
tm009()