#include<bits/stdc++.h>
using namespace std;
int main(){
	int x,a,b,c,d,e;
	cin>>x;
	a=x%10;
	b=x/10%10;
	c=x/100%10;
	d=x/1000%10;
	e=x/10000;
	x=a+b+c+d+e;
	cout<<x;
}
/**************************************************************
	Problem: 1418
	User: zengyixuan
	Language: C++
	Result: Accepted
	Time:19 ms
	Memory:2072 kb
****************************************************************/