#include <iostream>
#include <string>
using namespace std;

int main()
{
    string s;
    cin >> s;

    int ans = 0;
    for(int i = 0; i < s.length(); i++){
        switch (s[i]) {
		case '0':
            ans += 10;
            break;
		case '1':
            ans += 1;
            break;
		case '2':
            ans += 2;
            break;
		case '3':
            ans += 3;
            break;
		case '4':
            ans += 4;
            break;
		case '5':
            ans += 5;
            break;
		case '6':
            ans += 6;
            break;
		case '7':
            ans += 7;
            break;
		case '8':
            ans += 8;
            break;
		case '9':
            ans += 9;
            break;
        }
    }

    cout << ans << endl;

    return 0;
}