#include <iostream>
using namespace std;
int main() {
int a,b,c,d,e,f,g,x,y;
cin >> a;
b = a % 10;
c = a / 10 % 10;
d = a / 100 % 10;
e = a / 1000 % 10;
f = a / 10000 % 10;
g = a / 100000 % 10;
x = a / 1000000 % 10;
y = b+c+d+e+f+g+x;
cout<< y <<endl;
return 0;
}
//2016 12 20 18 20 36