#include <stdio.h>
#include <string.h>
#define SWAP(type, a, b) {type tmp=a; a=b; b=tmp;}

void Sort(char *arr, int n) {
  int h=1;
  for (int h_tmp=1; h_tmp<n/9; h_tmp=h_tmp*3+1) {
    h=h_tmp;
  }
  while (h) {
    for (int i=h; i<n; i++) {
      for (int j=i; j>=h && arr[j-h]<arr[j]; j-=h) {
        SWAP(int, arr[j], arr[j-h]);
      }
    }
    h/=3;
  }
}

int main() {
  char x[10000];
  scanf("%s", x);
  int size=strlen(x);
  Sort(x, size);

  char t=x[size-1];
  int flg=0;
  for (int i=size-2; i>=0; i--) {
    if (t!=x[i]) {
      SWAP(char, x[i], x[i+1]);
      flg=1;
      break;
    }
  }

  if (x[0]!='0' && flg) {
    printf("%s\n", x);
  } else {
    printf("-1\n");
  }
  return 0;
}