#include<bits/stdc++.h>
using namespace std;
int main(){
int n,a=0,b=0,c=0;
cin>>n;
a=n/10;
b=n%10;
if(a>b){
c=a;
a=b;
b=c;
}
cout<<a<<b;
return 0;
}
/**************************************************************
Problem: 1606
User: fuhoubin
Language: C++
Result: Wrong Answer
****************************************************************/