import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		String x = sc.next();
		sc.close();

		int[] a = new int[10];
		for (int i = 0; i < x.length(); i++) {
			a[x.charAt(i) - '0']++;
		}

		StringBuilder sb = new StringBuilder();
		boolean flg1 = false;
		int j = 0;
		for (int i = 9; i >= 0; i--) {
			if (a[i] > 0) {
				sb.append(i);
				a[i]--;
				j = i - 1;
				if (a[i] == 0) {
					flg1 = true;
				}
				break;
			}
		}
		for (int i = j; i >= 0; i--) {
			if (a[i] > 0) {
				if (flg1) {
					flg1 = false;
				} else {
					sb.append(i);
					a[i]--;
					break;
				}
			}
		}
		if (sb.length() < 2 || sb.charAt(0) == '0') {
			System.out.println(-1);
			return;
		}

		for (int i = 9; i >= 0; i--) {
			while (a[i] > 0) {
				sb.append(i);
				a[i]--;
			}
		}
		System.out.println(sb.toString());
	}
}