#include<iostream>
#include<string>
#include<algorithm>
#include<cctype>
#include<set>
#include<bitset>
#include<math.h>
#include<map>
#include<queue>
#include<iomanip>
using namespace std;

int main(){
    int sum1;
    string s;
    cin >> s;
    for (int i = 0; i < s.size(); i++){
        if (s[i] >'0' && s[i] <= '9') sum1 += s[i] - '0';
    }
    cout << sum1 << endl;
}