#include <bits/stdc++.h>
using namespace std;
int main(){
    string a;
    cin>>a;
    int i[3]={a[0]-'0',a[1]-'0',a[2]-'0'};
    sort(i,i+3);
    cout<<i[2]<<i[1]<<i[0];
    return 0;
}
/**************************************************************
	Problem: 1042
	User: linyuhang
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2076 kb
****************************************************************/