#include <iostream>
#include <string>
using namespace std;
void SortString(const string &str)
{
string strEnglishchar;
for(unsigned int i=0;i<str.length();++i)
{
if('a'<=str[i] && 'z'>=str[i])
strEnglishchar.push_back(str[i]);
if('A'<=str[i] && 'Z'>=str[i])
strEnglishchar.push_back(str[i]);
}
//insert sort
for(int j=1;j<int(strEnglishchar.length());++j)
{
char key=strEnglishchar[j];
int i=j-1;
while(i >= 0)
{
char key1=key;
char key2=strEnglishchar[i];
if('A'<=key && 'Z'>=key)
key1+=32;
if('A'<=strEnglishchar[i] && 'Z'>=strEnglishchar[i])
key2+=32;
if(key1 < key2)
{
strEnglishchar[i+1]=strEnglishchar[i];
--i;
}
else
{
break;
}
}
strEnglishchar[i+1]=key;
}
//output
unsigned int j=0;
for(unsigned int i=0;i<str.length();++i)
{
if('a'<=str[i] && 'z'>=str[i])
cout<<strEnglishchar[j++];
else if('A'<=str[i] && 'Z'>=str[i])
cout<<strEnglishchar[j++];
else
{
cout<<str[i];
}
}
}
int main()
{
string str;
getline(cin,str);
SortString(str);
return 0;
}