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

int conv[256];

int main()
{
	for (int i = 0; i <= 9; i++){
		conv[i + '0'] = i;
	}
	
	int res = 0;
	string s;
	cin >> s;
	for (char c : s){
		res += conv[c];
	}
	
	cout << res << endl;
}