#include<fstream.h>

ifstream f("numar.in");

void main()
{ long n;
  int aux,i,c1,c2,a[10],nr=0;
  f>>n;
  cout<<endl;
  while(n/10 && n%10<n/10%10)
  { nr++;
	a[nr]=n%10;
	n=n/10;
  }
  if(n<10) cout<<"nu exista";
  else
  { 	nr++;
	a[nr]=n%10;
	n=n/10;
	c1=n%10;
	n=n/10;
	i=1;
	while(a[i]<c1) i++;
	c2=i;
	aux=c1;
	c1=a[c2];
	a[c2]=aux;
	n=n*10+c1;
	for(i=1;i<=nr;i++) n=n*10+a[i];
	cout<<n;
  }
  
}