#include <bits/stdc++.h>
using namespace std;
int main(){
	string s;
	cin>>s;
	int i[3]={s[0]-'0',s[1]-'0',s[2]-'0'};
	sort(i,i+3);
	cout<<i[2]<<i[1]<<i[0];
	return 0;
}

/**************************************************************
	Problem: 1042
	User: zhouhongyi
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2076 kb
****************************************************************/