339A- Helpful Maths.

#include <iostream>

#include<vector>

#include<string>

#include<math.h>

#include<map>

#include<algorithm>

/***** S. M. Sabiul Hajjaj Sabit *****/

using namespace std;

template <typename T>long long int power(T a, T b)

{

    long long int pow=1;

    for(int i=0; i<b; i++)

    {

        pow *= a;

    }

    return pow;

}

///*********Write Code From Here*********///

int main()

{

    string s;

    vector<int> arr;

    cin>>s;

    for(int i=0; i<s.size(); i+=2)

    {

        int t =s[i] -'0';

        // cout<<t<<endl;

        arr.push_back(t);

    }

    sort(arr.begin(),arr.end());

    for(int i=0; i<arr.size(); i++)

    {

        cout<<arr[i];

        if(i+1<arr.size())

        {

            cout<<"+";

        }

    }

}