#include <stdio.h>
#include <stdlib.h>

int main(void){
	char str[10000] ;
	scanf("%s", str );
	int i, total;
	total = 0;
	for(i=0;i<10000;i++){
		if((str[i]>= '0') && (str[i]<= '9')){
			total += str[i] - '0';
		}else if(str[i] == '\0'){
			break;	
		}
	}
	printf("%d", total);
}