import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
int n = in.nextInt();
in.close();
int sum = sum_dig(n);
System.out.println(sum);
}
//递归
public static int sum_dig(int n){
if (n > 0){
return n%10 + sum_dig(n/10);
} else {
return n;
}
}
} import java.util.Scanner;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
// 注意 hasNext 和 hasNextLine 的区别
while (in.hasNextInt()) { // 注意 while 处理多个 case
int a = in.nextInt();
int sum = 0;
while(a!=0) {
sum+=a%10;
a=a/10;
}
System.out.println(sum);
}
}
} import java.util.Scanner;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
String s=in.nextLine();
String[] sList=s.split("");
int a=0;
for(int i=0;i<sList.length;i++){
a=a+Integer.valueOf(sList[i]);
}
System.out.println(a);
}
} import java.util.Scanner;
public class Main{
public static void main(String[] args){
Scanner sc=new Scanner(System.in);
String str=sc.nextLine();
int sum=0;
for(int i=0;i<str.length();i++){
sum+=Integer.parseInt(str.substring(i,i+1));
}
System.out.print(sum);
}
} import java.util.*;
public class Main {
public static void main(String[] arg) {
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
String a = Integer.toString(n);
int len = a.length();
int sum = 0;
for(int i =1;i<=len;i++){
int ge = n%10;
n = n/10;
sum += ge;
}
System.out.println(sum);
}
} import java.util.*;
public class Main {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
while(scanner.hasNext()){
String str = scanner.next();
int sum = 0;
for(int i = 0;i < str.length();i++){
sum = sum + (str.charAt(i) - '0');
}
System.out.println(sum);
}
}
}