import java.util.*;

public class Main {
 	public static void main (String[] args) {
		Scanner sc = new Scanner(System.in);
		char[] arr = sc.next().toCharArray();
		int length = arr.length;
		Arrays.sort(arr);
		char max = arr[length - 1];
		for (int i = 0; i < length - 1; i++) {
		    if (arr[i] == max || (i == length - 2 && arr[i] == '0')) {
		        break;
		    }
		    if (arr[i] == arr[i + 1]) {
		        continue;
		    }
		    char tmp = arr[i];
		    arr[i] = arr[i + 1];
		    arr[i + 1] = tmp;
		    StringBuilder sb = new StringBuilder(new String(arr));
		    sb.reverse();
		    System.out.println(sb);
		    return;
		}
		System.out.println(-1);
   }
}