#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;

int main()
{
	char s[201];
	int i;
	while(gets(s))
	{
		sort(s,s+strlen(s));
		puts(s);
	} 
	return 0;
}
/**************************************************************
	Problem: 2201
	User: admin
	Language: C++
	Result: Accepted
	Time:10 ms
	Memory:1040 kb
****************************************************************/