import java.util.Scanner;

public class Main {
    public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);
        // 入力
        String sss = sc.next();
        // 出力
        int val = Integer.parseInt(sss);
        int len = sss.length();
        int num = 0;
        for (int i = 0; i < len; i++) {
            num += val & 0x01;
            val >>= 1;
        }
        System.out.println(num);
        sc.close();
    }
}

/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