#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: wengsihan
	Language: C++
	Result: Accepted
	Time:10 ms
	Memory:2072 kb
****************************************************************/