#include <iostream>

int main(void){
  int sum=0;
  int x;
  
  std::string s = "hello world!";
  std::cin >> s;
  
  const char* c = s.c_str();
  for(int i=0;i<s.length();i++){
	//std::cout << c[i] <<std::endl;
    x = (int)(c[i]);
    if(x>48 && x<58){
      sum += (x-48);
    }
  }
  std::cout << sum;
}