#include<bits/stdc++.h>
using namespace std;
int main(){
	int x,y,a,z;
	cin>>a;
	x=a/10;
	y=a%10;
	z=y*10+x;
	if(a<z){
		cout<<z;	
	}
	else cout<<a; 
}
/**************************************************************
	Problem: 1625
	User: panyuchen
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2072 kb
****************************************************************/