include <bits/stdc++.h>

using namespace std;

int main() {

string z, x;
int q = 0, w = 0;
getline(cin, z);
for (int i = 0; i < z.size(); i++) {
	if ((z[i] - '0') % 2 != 0) {
		w += z[i] - '0';
	}
}
cout << w;
return 0;

}