#include<bits/stdc++.h>
using namespace std;
int x,a,b;
int main(){
	cin>>x;
	a=x/10;
	b=x%10;
	cout<<a+b;
	return 0;
}
/**************************************************************
	Problem: 1605
	User: zhangziang
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/