#include<iostream>
#include<string>
#include<map>
#include<queue>
using namespace std;
map<string,bool> vis;
struct zt
{
	string str;
	long long ans;
};
long long cz[10] = {0,-1,+1,-3,+3};
int main()
{
	string st;
	cin >> st;
	if(st == "123804765")
	{
		cout << 0;
		return 0;
	}
	queue<zt> q;
	q.push({st,0});
	while(! q.empty())
	{
		zt head = q.front();
		q.pop();
		long long k;
		for(long long i=0;i<head.str.size();i++)
		{
			if(head.str[i] == '0')
			{
				k = i;
				break;
			}
		}
		for(long long i=1;i<=4;i++)
		{
			long long f = k-cz[i];
			if(f >= 0 && f < 9)
			{
				string d = head.str;
				swap(d[f],d[k]);
				if(vis.find(d) == vis.end())
				{
					q.push({d,head.ans+1});
					vis[d] = 1;
					if(d == "123804765")
					{
						cout << head.ans+1;
						return 0;
					}
				}
			}
		}
	}
	return 0;
}