#include <cstdlib>
#include <iostream>

#include <typeinfo>
using namespace std;
int main(){
char s[1000];
cin>>s;
int count =0;
for(int i=0;i<1000;i++){

    if(s[i]=='\0'){
        cout<<count;
        break;
    }
    if(s[i]=='0'){
        count+=10;
    }else{
        count+=s[i]-48;

    }
}
}