#include<bits/stdc++.h> 
using namespace std;
int main(){
    int n,g,s;
    cin>>n;
    g=n%10;
    s=n/10;
    if(s>g){
        cout<<s+g*10;
    }else{
        cout<<s+g*10;
}
} 
/**************************************************************
	Problem: 1707
	User: wangyiyang
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/