s=input()
d={}
c=1
l=[]
s1=''
for i in range(0,len(s)):
   c=1
   for j in range(1,len(s)):
       if i<j and s[i]==s[j] and s[i] not in l:
          
               c+=1
       
               d[s[i]]=c    

   l.append(s[i])    

if len(d)==0:
    print('#')

else:
 for i in range(0,len(s)):
    if s[i] not in list(d.keys()):
        print(s[i])
for k in sorted(s):
    s1+=k
    
print(s1)