import java.util.Scanner;
class Main{
    public static void main(String[] args) {
        Scanner scn=new Scanner(System.in);
        String x=scn.next();
       System.out.println(Integer.parseInt(String.valueOf(x.charAt(0)))+Integer.parseInt(String.valueOf(x.charAt(1)))+Integer.parseInt(String.valueOf(x.charAt(2))));
    }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz