#include <stdio.h>

int
findSmallestNumber (int arr[], int len)
{
  int min = arr[0];
  for (int i = 0; i < len; i++)
    {
      if (min > arr[i])
    {
      min = arr[i];
    }
    }
  return min;
}

int
all_even (int number)
{
  int i = 0, digit;
  int odd = 0;
  int num = number;
  while (num != 0)
    {
      number = num / 10;
      digit = num % 10;

      if (digit % 2 != 0)
    {
      odd = 1;
      break;
    }
      num = number;
    }

  if (odd == 1)
    {
      return 0;
    }
  else
    {
      return 1;
    }
}

int
main ()
{

  int m, n, k = 0, allEven[100];
  scanf ("%d%d", &m, &n);

  for (int i = m; i < n; i++)
    {
      if (all_even (i) == 1)
    {
      allEven[k] = i;
      k++;
    }
    }


  if (k == 0)
    printf ("NE");
  else
    printf ("%d", findSmallestNumber (allEven, k));

  return 0;
}