#include<bits/stdc++.h>

using namespace std;

const int dx[] = {,,-,};

const int dy[] = {-,,,};

const int MAXS =  << ;

struct info

{

        int mp[][];

        int step;

} ;

int i,j,k,goal,tx,ty,l,r,state;

int mp[][],g[][];

info q[MAXS];

info cur,tmp;

bool visited[MAXS];

inline bool valid(int x,int y)

{

        return x >  && x <=  && y >  && y <= ;

}

inline int get(int a[][])

{

        int i,j,ret = ;

        int b = ;

        for (i = ; i <= ; i++)

        {

                for (j = ; j <= ; j++)

                {

                        ret += a[i][j] * b;

                        b <<= ;

                }

        }

        return ret;

}

int main()

{

        for (i = ; i <= ; i++)

        {

                for (j = ; j <= ; j++)

                {

                        mp[i][j] = getchar() - '';

                }

                getchar();

        }

        getchar();

        for (i = ; i <= ; i++)

        {

                for (j = ; j <= ; j++)

                {

                        g[i][j] = getchar() - '';

                }

                getchar();

        }

        goal = get(g);

        visited[get(mp)] = true;

        if (visited[goal])

        {

                printf("0\n");

                return ;

        }

        l = r = ;

        memcpy(q[].mp,mp,sizeof(q[].mp));

        q[].step = ;

        while (l <= r)

        {

                cur = q[l];

                l++;

                for (i = ; i <= ; i++)

                {

                        for (j = ; j <= ; j++)

                        {

                                if (cur.mp[i][j] == )

                                {

                                        for (k = ; k < ; k++)

                                        {

                                                tx = i + dx[k];

                                                ty = j + dy[k];

                                                if (valid(tx,ty) && cur.mp[tx][ty] == )

                                                {

                                                        swap(cur.mp[i][j],cur.mp[tx][ty]);

                                                        state = get(cur.mp);

                                                        if (!visited[state])

                                                        {

                                                                visited[state] = true;

                                                                if (state == goal)

                                                                {

                                                                        printf("%d\n",cur.step+);

                                                                        return ;

                                                                }

                                                                r++;

                                                                memcpy(q[r].mp,cur.mp,sizeof(q[r].mp));

                                                                q[r].step = cur.step + ;

                                                        }

                                                        swap(cur.mp[i][j],cur.mp[tx][ty]);

                                                }

                                        }

                                }

                        }

                }

        }

        return ;

}