#include<iostream>
#include<string>
using namespace std;
int ctoi(char c){
    if(c >='0' && c<='9'){
        return c-'0';
    }
    return -1;
}
int main()
{
    string str;
    cin>>str;
    int score = 0;
    for(int i=0;i<str.length();i++){
        score += ctoi(str[i]);
        if(str[i]=='0'){
            score+=10;
        }
    }
    cout<<score;
    return 0;
}