#include <stdio.h>
#include <string.h>
typedef int Position;
// 快排
Position partion(char *str, int low, int high)
{
char pivot = str[low];
while (low < high)
{
while (low < high && str[high] >= pivot)
high--;
str[low] = str[high];
while (low < high && str[low] <= pivot)
low++;
str[high] = str[low];
}
str[low] = pivot;
return low;
}
void QuickSort(char *str, int low, int high)
{
if (low < high)
{
Position pivotProps = partion(str, low, high);
QuickSort(str, low, pivotProps - 1);
QuickSort(str, pivotProps + 1, high);
}
}
int main()
{
char str[200];
while (scanf("%s", str) != EOF)
{ // 注意 while 处理多个 case
QuickSort(str, 0, strlen(str) - 1);
printf("%s", str);
}
return 0;
}