#define _USE_MATH_DEFINES
#include <cstdio>
#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <complex>
#include <string>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <numeric>
#include <limits>
#include <climits>
#include <cfloat>
#include <functional>
using namespace std;

int main()
{
    string s;
    cin >> s;
    s = string(8 - (s.size() - 1) % 9, '0') + s;
    int n = s.size();

    vector<long long> v(1, 0);
    for(int i=0; i<n; i+=9){
        vector<long long> w(v.size()+1, 0);
        w[0] = stoi(s.substr(i, 9));

        for(unsigned j=0; j<v.size(); ++j){
            w[j] += v[j] * 1000000000;
            w[j+1] = w[j] >> 32;
            w[j] &= (1LL << 32) - 1;
        }
        if(w.back() == 0)
            w.pop_back();
        v.swap(w);
    }

    int ans = 0;
    for(unsigned i=0; i<v.size(); ++i){
        bitset<32> bs(v[i]);
        ans += bs.count();
    }
    cout << ans << endl;

    return 0;
}