#include<bits/stdc++.h>
using namespace std;

int main(){
	int n,a,b,c;
	cin>>n;
	a=n%10;
	b=n/10%10;
	c=n/100%10;
	if(a<b) swap(a,b);
	if(a<c) swap(a,c);
	if(b<c) swap(b,c);
	cout<<a<<b<<c;
	
}

/**************************************************************
	Problem: 1042
	User: linzihang
	Language: C++
	Result: Accepted
	Time:10 ms
	Memory:2072 kb
****************************************************************/