#include<stdio.h>
#include<stdlib.h>

void run(void){
  char s[10001];
  scanf("%s",s);

  int sum=0;
  int i=0;
  while(s[i]!='\0'){
    if(s[i]>='0' && s[i]<='9'){
      sum+=(s[i]-'0');
    }
    i++;
  }
  printf("%d\n",sum);
  return;
}

int main(void){
  run();
  return 0;
}