#include<bits/stdc++.h>
using namespace std;
int main() {
	int s,a,b,h;
	scanf("%d",&s);
	a=s/10;
	b=s%10;
	h=a+b;
	printf("%d",h); 
    return 0;
}

/**************************************************************
	Problem: 1605
	User: huangcanwu
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/