#include <bits/stdc++.h>
#include <iostream>
#include <string>
#include <stdlib.h>
using namespace std;

int main() {
string s;
cin>>s;
int a;
int sum=0;
for (int i = 0; i < s.length(); ++i) {
	a=s[i]-48;
	if(a==1||a==2||a==3||a==4||a==5||a==6||a==7||a==8||a==9){
		sum+=a;
	}
}
cout<<sum<<endl;
}