#include<bits/stdc++.h>
#define ull unsigned long long
#define ll long long
#define ri register
#define For(iee,eei,eie) for(iee=eei;iee<=eie;iee++)
using namespace std;
template <class T>
inline void read(T &x) {
    x=0;
    ri char c = getchar();
    for (; !isdigit(c); c = getchar());
    for (; isdigit(c); c = getchar()) x = x * 10 + (c ^ 48);
}
string a;
ll n,ans,top;

int main()
{
    ll i;
    cin>>a;
    n=a.size();
    for(i=0;i<n;i++)
        a[n+i]=a[n-i-1];
    for(i=0;i<n;i++)
        a[i]=a[n+i];
    while(top<n-1)
    {
        ans++;
        if(a[top]=='1')
        {
            for(i=top;a[i]=='1';i++)
                a[i]='0';
            if(i==n)n++; 
            a[i]='1';
        }
        else top++;
    }
    if(a[top]=='0')ans++;
    cout<<ans;
    return 0;
}

数据：1010101001001111000111110011111000010101011111101010