#include <bits/stdc++.h>
using namespace std;
int main() {
    int a,b;
    float c,d;
    cin>>a;
	c=a/10;
	d=a%10;
	b=d*10+c;
	if(a<b)
	{
		swap(a,b);
	}
	cout<<a;
    return 0;
}
/**************************************************************
	Problem: 1625
	User: fuhoubin
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2072 kb
****************************************************************/