#include<bits/stdc++.h>

using namespace std;
int visited[1010][1010];
int level[1010][1010];
int row[4]= {0,-1,0,1};
int col[4]= {1,0,-1,0};
struct TwoD
{
    int r;
    int c;
};
int bfs(TwoD s, TwoD e,int r,int c)
{
    queue<TwoD>Q;
    Q.push(s);
    visited[s.r][s.c]=1;
    level[s.r][s.c]=0;
    while(!Q.empty())
    {
        if(visited[e.r][e.c]==1)
            return level[e.r][e.c];
        TwoD u;
        u=Q.front();
        Q.pop();
        for(int i=0; i<4; i++)
        {
            TwoD p;
            p.r=u.r+row[i];
            p.c=u.c+col[i];
            if(p.r>=0 and p.r<r and p.c>=0 and p.c<c)
                if(visited[u.r+row[i]][u.c+col[i]]==0)
                {
                    visited[u.r+row[i]][u.c+col[i]]=1;
                    level[u.r+row[i]][u.c+col[i]]=level[u.r][u.c]+1;
                    Q.push(p);
                }
        }
    }
    return 0;


}
int main()
{
    int r, c;
    while((cin>>r>>c) and r and c)
    {
        memset(visited, 0, sizeof(visited[0][0]) * 1010 * 1010);
        memset(level, 0, sizeof(level[0][0]) * 1010* 1010);
        int rows;
        cin>>rows;
        while(rows--)
        {
            int rnum;
            cin>>rnum;
            int bnum;
            cin>>bnum;
            while(bnum--)
            {
                int cnum;
                cin>>cnum;
                visited[rnum][cnum]=1;
            }

        }
        TwoD spair,epair;
        cin>>spair.r>>spair.c;
        cin>>epair.r>>epair.c;
        int steps=bfs(spair, epair, r, c);
        cout<<steps<<endl;
    }
}