#include <stdio.h>

int main(void){
	char num[10];
	scanf("%s",num);
	int total = 0;
	for(int i = 0;i < 9;i ++){
		int intNum = num[i] - '0'; 
		if(num[i] == '0'){
			total += 10;
		}else{
			total += intNum;
		}
	}
	printf("%d",total);
}