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

int main() {
	int a, b, c, d, e,f;
	cin >> a;
	b = a % 10;
	c = a / 10 % 10;
	d = a / 100 % 10;
	e = a / 1000;
    f=e+d+c+b+a;
    cout<<f;
	return 0;
}