#include<stdio.h>
#include<string.h>
#include<stdlib.h>
int main(void){
char s[100];scanf("%s",s);
int sum=0;

for(int i=0;i<9;i++){
if(s[i]=='0'){sum=sum+10;}
else {sum=sum+s[i]-'0';}
}
printf("%d\n",sum);
}