#include<bits/stdc++.h>

using namespace std;

int bg,ed = 123804765;
int a[10];

map<int,int> m[2];
queue<pair<int,bool> > q;

bool check1(int x,int op){
	for(int i = 9;i>0;i--) a[i] = x%10,x/=10;
	int p;
	for(int i = 9;i>=1;i--){ 
		if(a[i]==0){
			p = i;
			break;
		}
	} 
	if(op==1){
		if(p<=3) return -1; 
		else swap(a[p],a[p-3]);	
	}else if(op==2){
		if(p>=7) return -1; 
		else swap(a[p],a[p+3]);	
	}else if(op==3){
		if(p%3==1) return -1; 
		else swap(a[p],a[p-1]);
	}else if(op==4){
		if(p%3==0) return -1;
		else swap(a[p],a[p+1]);
	}
	x = 0;
	for(int i = 1;i<=9;i++) x = x*10+a[i];
	return x; 
}

void check2(int x,pair<int ,bool > h){
	if(x==-1){
		return ;
	}
	if(m[h.second^1].count(x)==true){
		cout<<m[h.second^1][x]+m[h.second][h.first]+1<<endl;
		exit(0);
	} else{
		m[h.second][x] = m[h.second][h.first]+1;
		q.push(make_pair(x,h.second));
	}
} 

int main(){
	cin>>bg;
	if(bg==ed){
		cout<<0;
		return 0;
	}
	q.push(make_pair(bg,0));
	q.push(make_pair(ed,1));
	while(!q.empty()){
		pair<int,bool> h = q.front();
		q.pop();
		int x = check1(h.first,1);check2(x,h);
		x = check1(h.first,2);check2(x,h);
		x = check1(h.first,3);check2(x,h);
		x = check1(h.first,4);check2(x,h);
	}
	return 0;
}