#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main(){
  // input
  string S;
  cin >> S;
  int total = 0;
  for(int i=0;i<S.size();i++){
    if(('0' <= S[i]) and (S[i] <='9')){
      total += int(S[i] - '0');
    }
  }


  cout << total << endl;
  // output 
}