#include <bits/stdc++.h>
#define int long long 
using namespace std;

signed main() {
string S;
cin >> S;

int ans = 0;
for( int i = 0; i < S.size(); i++ ){
if( S.at(i) == '0' ) ans += 10;
else{
int n = S.at(i) - '0';
ans += n;
}
}
cout << ans << endl;

}