#include<bits/stdc++.h>
using namespace std;
int main(){
    string s;
    cin>>s;
    int c=0;
    for(int i=0;i<s.size();i++){
        if(s[i]>='0'&&s[i]<='9'){
            c+=s[i]-'0';
        }
    }
    cout<<c<<endl;
}