#include <bits/stdc++.h>
#define INF 990000000
//29
using namespace std;
int ctoi(const char c){
  switch(c){
    case '0': return 0;
    case '1': return 1;
    case '2': return 2;
    case '3': return 3;
    case '4': return 4;
    case '5': return 5;
    case '6': return 6;
    case '7': return 7;
    case '8': return 8;
    case '9': return 9;
    default : return -1;
  }
}
int main() {
string s;
cin>>s;
int res=0;
for(int i=0;i<(int)s.size();i++){
if(ctoi(s[i])==0)res+=10;
else res+=ctoi(s[i]);
}

cout << res<<endl;





}