#include<bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define show(x) cerr<<#x<<"="<<x<<"\n"
using namespace std;

int n,m;
string s;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.precision(10);
    cout<<fixed;
#ifdef LOCAL_DEFINE
    FILE *stream1;
    //FILE *stream2;
    stream1=freopen("in","r",stdin);
    //stream2=freopen("out","w",stdout);
    if(stream1==NULL)return 0;
    //if(stream2==NULL)return 0;
#endif
    cin>>s;
    int n=(int)s.size();
    int ans=0;
    for(int i=0;i<n;i++){
      if(s[i]=='0')ans+=10;
      else ans+=s[i]-'0';
    }
    cout<<ans<<endl;
#ifdef LOCAL_DEFINE
    cerr<<"Time elapsed: "<<1.0*clock()/CLOCKS_PER_SEC<<"s.\n";
    fclose(stream1);
    //fclose(stream2);
#endif
    return 0;
}