#include <stdio.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(){
  int N;
  int i=1,j;
  int max;
  char buf[10];
  int len;
  int tmp;
  scanf("%d",&N);
  itoa(N,buf,10);
  len=strlen(buf);
  
  while(i<len && buf[i]>=buf[0])i++;
  if(i==len)i=0;

  max=0;
  for(j=1;j<len;j++){
    if(buf[max]<=buf[j])max=j;
  }

  // printf("replace %d %d\n",i,max);
  if(buf[0]==buf[max]){
  tmp=buf[i];
  buf[i]=buf[max];
  buf[max]=tmp;
  }
  else{
    tmp=buf[0];
    buf[0]=buf[max];
    buf[max]=tmp;
  }
  printf("%s\n",buf);
  
  return 0;
}