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