#include <stdio.h>
#include <memory.h>

#define MAX 1000000

char r[10][MAX];

int main(void) {
	char b;
	int bit, temp, tail[10] = { 0 };

	for (int i = 0; i < 10; i++) {
		r[i][0] = '\0';
	}

	while (1) {
		scanf("%c", &b);
		if (b == '\n')
			break;
		r[b - 0x30][tail[b - 0x30]] = b;
		tail[b - 0x30]++;
	}

	for (int i = 9; i >= 0; i--) {
		r[i][tail[i]] = '\0';
		printf("%s", r[i]);
	}
	printf("\n");

	return 0;
}