#include<bits/stdc++.h>
using namespace std;
int main(){
    int n;
    cin>>n;
    cout<<n%10+n/10;
    
    
    
    
    
	
	
}
/**************************************************************
	Problem: 1605
	User: lvrenxiang
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/