include <bits/stdc++.h> using namespace std; int a[10];

int main() {

long long n; cin >> n; while (n != 0) {

int x = n % 10;
a[x]++;
n = n / 10;

} for (int i = 1; i <= 9; i++) {

if (a[i] != 0) {
	cout << i;
	a[i]--;
	break;
}

} for (int i = 0; i <= 9; i++) {

if (a[i] != 0) {
	while (a[i]--) {
		cout << i;
	}
}

} return 0; }