#include<bits/stdc++.h>
using namespace std;
int a,s,d,f,g,j,h;
int main(){
    cin>>a;
    s=a%10;
    d=a/10%10;
    f=a/100%10;
    g=a/1000%10;
    j=a/10000%10;
    h=s+d+f+g+j;
    printf("%d",h);
}
/**************************************************************
	Problem: 1418
	User: chenyichuen
	Language: C++
	Result: Accepted
	Time:13 ms
	Memory:2072 kb
****************************************************************/