#include <bits/stdc++.h>
#define int long long
using namespace std;
int f(string s){
    int cnt=0;
    for(int i=0;s[i];++i){
        int x = 0;
        for(int j=i;j<n;++j){
            x = 2*x+(s[j]-'0'); 
            if(x>0&&(x&(x-1))==0){  
                cnt++;
                break;
            }
        }
    }
    return cnt;
}
signed main() {
    string s;
    cin >> s;
    int t = f(s);
    cout<<t<<endl;
    return 0;
}