#include <bits/stdc++.h>
using namespace std;
int main(){
	int a,s,d,f,g;
	cin>>a;
	s=a%10;
	d=a/10%10;
	f=a/100;
	if(f<d){
		swap(f,d);
	}
	if(f<s){
		swap(f,s);
	}
	if(d<s){
		swap(d,s);
	}cout<<f<<d<<s;
}
/**************************************************************
	Problem: 1042
	User: tonghuawei
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/