#include <iostream>
#include <string>
using namespace std;
int main(){
	int score=0,S;
	cin>>S;
	for(int x=0;x<9;x++){
		int y=S%10;
		S/=10;
		if(y==0){
			score+=10;
		}else{
			score+=y;
		}
	}
	cout<<score<<endl;
	return 0;
}