#include <stdio.h>
#include <stdlib.h>
#include <string.h>
char *itoa( int val, char *a, int radix )
{
 char *p = a;
 unsigned int v = val;
 int n = 1;
 while(v >= radix){
   v /= radix;
   n++;
 }
 p = a + n;
 v = val;
 *p = '\0';
 do {
   --p;
   *p = v % radix + '0';
   if(*p > '9') {
     *p = v % radix - 10 + 'A';
   }
   v /= radix;
 } while ( p != a);
 return a;
}
int main(){
  long int N;
  int i,j;
  char buf[10],buf2[0];
  int len;
  int tmp;
  long int x,max;
  scanf("%ld",&N);
  itoa(N,buf,10);
  itoa(N,buf2,10);
  len=strlen(buf);
  
  max=atoi(buf);
 
  for(i=0;i<len-1;i++){
    for(j=i+1;j<len;j++){
      tmp=buf2[i];
      buf2[i]=buf2[j];
      buf2[j]=tmp;
      x=atoi(buf2);
      if(max<x)max=x;
      tmp=buf2[i];
      buf2[i]=buf2[j];
      buf2[j]=tmp;
    }
  }
  printf("%ld\n",max);
  return 0;
}