#include <bits/stdc++.h>
using namespace std;
#define REP(i,n) for (int i = 0; i < (n); i++)
typedef long long ll;
// Welcome to my source code!

int main() {
    string s, t;
    cin >> s;
    REP(i, s.size()) {
        if (isdigit(s[i])) t += s[i];
    }
    int sum = 0;
    REP(i, t.size()) {
        string tmp = t.substr(i,1);
        int val = stoi(tmp);
        sum += val;
    }
    cout << sum << endl;
}