#include<cstdio>
#include<unordered_map>
#include<cstring>
#include<queue>
#include<algorithm>
using namespace std;
typedef long long LL;
const LL KEndStatus=123804765;
unordered_map<LL,int> res;
int main()
{
#ifdef local
	freopen("pro.in","r",stdin);
#endif
	res[KEndStatus]=0;
	queue<LL> Q;
	Q.push(KEndStatus);
	while(Q.size())
	{
		LL u=Q.front(); Q.pop();
		int distu=res[u];
		int rid[9]={2,2,2,1,1,1,0,0,0};
		int cid[9]={2,1,0,2,1,0,2,1,0};
		int dr[4]={0,-1,0,1};
		int dc[4]={-1,0,1,0};
		int mpu[3][3],ur,uc;
		LL utmp=u;
		for(int i=0;i<9;i++)
		{
			mpu[rid[i]][cid[i]]=utmp%10;
			utmp/=10;
			if(mpu[rid[i]][cid[i]]==0)
			{
				ur=rid[i];
				uc=cid[i];
			}
		}
		for(int f=0;f<4;f++)
		{
			int vr=ur+dr[f],vc=uc+dc[f];
			if(vr==-1||vr==3||vc==-1||vc==3) continue;
			swap(mpu[ur][uc],mpu[vr][vc]);
			LL v=0;
			for(int r=0;r<3;r++)
				for(int c=0;c<3;c++)
					v=v*10+mpu[r][c];
			if(v!=KEndStatus&&res[v]==0)
			{
				res[v]=distu+1;
				Q.push(v);
			}
			swap(mpu[ur][uc],mpu[vr][vc]);
		}
	}
	LL query;
	scanf("%lld",&query);
	printf("%d\n",res[query]);
	return 0;
}