#include <iostream>

int ctoi(char c) {
	return (int)(c - 48);
}

int main () {
	char s[9];
	std::cin >> s;

	int ans = 0;
	for (int i = 0; i < 9; ++i) {
		ans += s[i] == '0' ? 10 : ctoi(s[i]);
	}

	std::cout << ans << std::endl;
}