#include<iostream>
using namespace std;
int main() {
 string s;
 cin >> s;
 int n=s.size();
 int ans=0;
 int i;
 for(i=0;i<n;i++){
     if(0<=s[i]&&s[i]<=9){
         
     ans=ans+s[i];
 }
}
cout << ans << endl;
}