#include <bits/stdc++.h>
#define rep(i,n)for(int i=0;i<(n);i++)
#define INF 0x3f3f3f3f
#define INFL 0x3f3f3f3f3f3f3f3f
#define EPS (1e-10)
#define MOD 1000000007
using namespace std;
typedef long long ll;
typedef pair<int,int>P;

signed main(){
	string s;cin>>s;
	int cnt=0;
	for(char c:s){
		if(c=='0')cnt+=10;
		else cnt+=c-'0';
	}
	cout<<cnt<<endl;
}