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

int main() {
    
    string s,S;
    vector<long> list;
    int ans;
    cin >> s;
    for(long i = 0; i < s.size(); i++){
        try {
            list.push_back(stoi(s.substr(i,1)));
        } catch (const std::invalid_argument& e) {
        }
    }
    for(int i = 0; i < list.size(); i++){
        ans += list[i];
    }
    cout << ans << "\n";
    
    return 0;
}