#include <stdio.h>
int main()
{
	int a,a0,a1,a2,a3,a4,b1,b2,b3,x;
	scanf("%d",&a);
	a0=a/10000;
	a1=a%10000;
	a2=a1%1000;
	a3=a2%100;
	a4=a3%10;
	
	b1=a1/1000;
	b2=a2/100;
	b3=a3/10;
	
	x=a0+b1+b2+b3+a4;
	
	printf("%d",x);
	return 0;
}