#include <iostream>
#include <string>
using namespace std;


int main(){
  int i = 0;
  string str;
  int sum = 0;
  cin >> str;
  while(!(str[i] == '\0')){
    //cout << password[i] << endl;
    if (str[i]>='0' && str[i]<='9'){
      sum += str[i] - '0';
    }
    i++;
  }
  cout << sum << endl;
}