#include <bits/stdc++.h>
using namespace std;
string s;
int len;
struct jgt
{
    int ls,rs;
    jgt(){ls=rs=0;}
}a[3000],b[3000];
int cnt=1;
void dfs1(int rt)
{
    int c=rt-1;
    if(s[c]=='1'||s[c]=='3')
    {
        a[rt].ls=++cnt;
        dfs1(cnt);
    }
    if(s[c]=='2'||s[c]=='3')
    {
        a[rt].rs=++cnt;
        dfs1(cnt);
    }
}
int ct=1,p=1;
void dfs2(int rt)
{
    if(a[rt].ls)
    {
        if(!b[p].ls)
            b[p].ls=++ct;
        int o=p;
        p=b[p].ls;
        dfs2(a[rt].ls);
        p=o;
    }
    if(a[rt].rs)
    {
        if(!b[p].rs)
            b[p].rs=++ct;
        int o=p;
        p=b[p].rs;
        dfs2(a[rt].rs);
        p=o;
    }
}
int main()
{
    freopen("movement.in","r",stdin);
    freopen("movement.out","w",stdout);
    cin>>s;
    len=s.size();
    dfs1(1);
    if(a[1].ls&&a[1].rs)
    {
        for(int i=1;i;i=a[i].ls)
            if(a[i].rs)
                dfs2(a[i].rs);
        int tp=ct;
        for(int i=1;i<=ct;i++) b[i].ls=b[i].rs=0;
        ct=1;
        for(int i=1;i;i=a[i].rs)
            if(a[i].ls)
                dfs2(a[i].ls);
        ct=min(ct,tp);
    }
    else if(a[1].ls)
    {
        for(int i=1;i;i=a[i].ls)
            if(a[i].rs)
                dfs2(a[i].rs);
    }
    else if(a[1].rs)
    {
        for(int i=1;i;i=a[i].rs)
            if(a[i].ls)
                dfs2(a[i].ls);
    }
    cout<<ct*2+1;
    return 0;
}