/*

 * Main.c

 *

 *  Created on: 2014年1月25日

 *      Author: Shaobo

 */

#include <stdio.h>

#include <string.h>

int Partition(char data[], int from, int to){

    char pivot = data[from];

    while (from < to){

        while (from < to && data[to] >= pivot) --to;

        data[from] = data[to];

        while (from < to && data[from] <= pivot) ++from;

        data[to] = data[from];

    }

    data[from] = pivot;

    return from;

}

void QuickSort(char data[], int from, int to){

    int pivotpos = Partition (data, from, to);

    if (from < pivotpos-1)

        QuickSort(data, from, pivotpos-1);

    if (to > pivotpos)

        QuickSort(data, pivotpos+1, to);

}

int main(void){

    char input[21];

    int len;

    while (scanf ("%s", input) != EOF){

        len = strlen(input);

        QuickSort(input, 0, len-1);

        printf ("%s\n", input);

        while (getchar() != '\n')

            continue;

    }

    return 0;

}