C :

#include<stdio.h>   

int main(){  
	int x;
	scanf("%d",&x);
	
	int b = x / 100;
	int s = x / 10 % 10;
	int g = x % 10;
	
	printf("%d",b+s+g);
	
	return 0; 
} 

C++ :

#include<iostream>
using namespace std;
int main(){
	int a,b,c,x,s;
	cin>>x;
	a=x/100;
	b=x/10%10;
	c=x%10;
	s=a+b+c;
	cout<<s<<endl;
	
	
}

Pascal :

var n,g,s,b:longint;
begin
  read(n);
  g:=n mod 10;
  s:=n div 10 mod 10;
  b:=n div 100;
  writeln(g+s+b);
end.

Java :

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
			Scanner scanner=new Scanner(System.in);
			int m=scanner.nextInt();
			int a=m%1000/100;
			int b=m%100/10;
			int c=m%10;
			int d=a+b+c;
		System.out.print(d);  
			
	
			
	}
}

Python :

n=int(input())
a=n//100
b=n//10%10
c=n%10
print(a+b+c)