#include<bits/stdc++.h>
using namespace std;
int x,a,b,c,d,e;
int main(){
	cin>>x;
	a=x/10000; x%=10000;
	b=x/1000; x%=1000;
	c=x/100; x%=100;
	d=x/10; x%=10;
	e=x;
	cout<<a+b+c+d+e;
	return 0;
}
/**************************************************************
	Problem: 1418
	User: zhangziang
	Language: C++
	Result: Accepted
	Time:12 ms
	Memory:2072 kb
****************************************************************/