#include <iostream>
#include <cstdio>
#include <cmath>
#include <string>
#include <algorithm>
using namespace std;

int main() {
	string S;
	string c;
	int i,sum=0;
	cin>>S;
	for(i=0;i<S.size();i++){
		c = S[i];
		if("0"< c && c <= "9")	sum+=stoi(c);
	}
	
	cout<<sum<<endl;
}