#include <iostream>

using namespace std;

int main() {
    string s;
    
    cin >> s;
    
    int total = 0;
    for (int i = 0; i < s.length(); i++) {
        if (49 <= s[i] && s[i] <= 57) {
            total += s[i] - 48;
        }
    }
    
    cout << total << endl;
    
    return 0;
}