#include<iostream>
#include<string>

using namespace std;

int main(){
    string input;
    int outputNumber = 0,i,j;
    cin >> input;
    for(i=0;i<input.size();i++){
	try{
	    j = stoi(input.substr(i,1));
	    outputNumber += j;
	}
	catch(std::invalid_argument e){
	}
    }
    cout << outputNumber << endl;
    return 0;
}