#include <stdio.h>

int main(int argc, const char * argv[]) {
  char input[9];
  int number[9], digit, max, pos1, pos2, result;

  scanf("%s", input);
  
  for (digit = 0; input[digit] != '\0'; digit++)
    number[digit] = (int)(input[digit] - '0');

  for (pos1 = max = digit = 0; input[digit] != '\0'; digit++)
    if (number[digit] >= max) {
      max = number[digit];
      pos1 = digit;
    }
  
  for (pos2 = 0; number[pos2] >= max; pos2++);

  result = number[pos2];
  number[pos2] = number[pos1];
  number[pos1] = result;

  for (result = digit = 0; input[digit] != '\0'; digit++)
    result = result * 10 + number[digit];

  printf("%d\n", result);

  return 0;
}