#include<iostream>
#include<string>
using namespace std;
int main()
{
	int sum = 0;
	string s;
	cin >> s;
	for (char &c : s)
	{
		if (48 < c && c < 58) {
			sum += c - 48;
		}
	}
	cout << sum << "\n";
	return 0;
}