include<bits/stdc++.h>

using namespace std;
class solution {
public:
string sortstr(string str)
{
string str1 = "";//存放1-9数字
string str2 = "";//存放a-z小写字母
int len = str.size();
sort(str.begin(), str.end());
for (int i = 0; i < len; i++)
{
if (str[i] < 'a')
{
char a = str[i];
str1 += a;
}
else
{
char a = str[i];
str2 += a;
}

    }
    string str3 = str2 + str1;
    return str3;
}

};
int main()
{
string str;
cin>>str;
solution s;
string str1 = s.sortstr(str);
cout<<str1;
return 0;
}