#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,g,s,h=0;
	scanf("%d",&n);
	g=n%10;
	s=n/10%10;
	h=g+s;
	printf("%d",h);
	return 0;
}
/**************************************************************
	Problem: 1605
	User: xiaojingxuan
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2076 kb
****************************************************************/