#include <bits/stdc++.h>
using namespace std;

int main(){
    int n;
    cin>>n;
    if(n / 10 > n % 10){
    	cout<<n / 10;
	}else{
		cout<<n % 10;
	}
}
 

/**************************************************************
	Problem: 1622
	User: admin
	Language: C++
	Result: Accepted
	Time:14 ms
	Memory:2072 kb
****************************************************************/