#include <iostream>

#include <queue>
#include <stack>

using namespace std;

int main(){
    string str;
    int n = 0;

    queue <char> arr_queue[100];
    stack <char> arr_stack[100];


    cin >> str;
    string::iterator it = str.begin();

    while (it != str.end())
    {
        while (*it >= 65 && *it <= 90 && it != str.end())
        {
            arr_queue[n].push(*it);
            it++;
        }

        while (*it >= 91 && *it <= 122 && it != str.end())
        {
            arr_stack[n].push(*it);
            it++;
        }
        n++;
    }

    for(int i = 0; i < n; i++)
    {
        while (!arr_queue[i].empty()){
            cout << arr_queue[i].front();
            arr_queue[i].pop();
        }

        while (!arr_stack[i].empty()){
            cout << arr_stack[i].top();
            arr_stack[i].pop();
        }
    }

    return 0;
}


//a1b1a2b2a3b3...anbn

//ABCDEabcdeABCDEabcde

//a = 91 z = 122 b
//A = 65 Z = 90  a