#include <iostream>
#include <vector>
#include <map>
#include <algorithm>
using namespace std;

#define REP(i,s,e) for (i = s; i <= e; i++)
#define rep(i,n) REP (i,0,(int)(n)-1)
#define RREP(i,s,e) for (i = s; i >= e; i--)
#define rrep(i,n) RREP (i,(int)(n)-1,0)
#define INF (int)1e8
#define MOD 1004535809

typedef long long ll;

ll inv(ll x) {
    int n = MOD - 2;
    ll ret = 1;
    while (n) {
        if (n % 2) {
            ret *= x;
            ret %= MOD;
        }
        x *= x;
        x %= MOD;
        n /= 2;
    }
    return ret;
}

int num[1000000];

int main(void) {
    int i, n;
    string s;
    cin >> s;
    n = s.size();
    rep (i,n)
        num[i] = s[i] - '0';
    int ans = 0;
    while (true) {
        ans += num[n-1] % 2;
        int carry = 0;
        bool end = true;
        rep (i,n) {
            num[i] += carry;
            if (num[i] % 2)
                carry = 10;
            else
                carry = 0;
            num[i] /= 2;
            if (num[i] != 0) end = false;
        }
        if (end)
            break;
    }
    cout << ans << endl;
    return 0;
}