#include <iostream>
#include <string>
#include <math.h>
#include <vector>
#include<stdio.h>
#include<algorithm>
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n)  FOR(i,0,n)
#define all(x) (x).begin(),(x).end()
typedef long long ll;
#define SZ(x) ((int)(x).size())

using namespace std;

int main(){
	string s;
	int score = 0;
	cin >> s;
	REP(i, SZ(s)) {
		if (s[i] == '0') {
			score += 10;
		}
		else {
			score += s[i]-'0';
		}
	}
	cout << score << endl;
	return 0;
}