#include<bits/stdc++.h>
using namespace std;
int main(){
	int i,a,b,c,d,e;
	cin>>i;
	a=i%10;
	b=i/10%10;
	c=i/100%10;
	d=i/1000%10;
	e=i/10000%10;
	cout<<a+b+c+d+e;
}
/**************************************************************
	Problem: 1418
	User: baizhoudeyueguang
	Language: C++
	Result: Accepted
	Time:20 ms
	Memory:2072 kb
****************************************************************/