#include<iostream>#include<cstdio>#include<cstring>#include<algorithm>#include<queue>#define maxv 300500#define maxe 2000500#define inf 2147483647using namespace std;struct pnt{    int x,y,id;}p[maxv];struct edge{    int v,w,nxt;}e[maxe];int n,m,x,y,cnt=0,dis[maxv],nume=0,g[maxv],ans=inf;bool vis[maxv];queue <int> q;void addpnt(int x,int y){cnt++;p[cnt].x=x;p[cnt].y=y;p[cnt].id=cnt;}bool cmp1(pnt x,pnt y){if (x.x==y.x) return x.y<y.y;return x.x<y.x;}bool cmp2(pnt x,pnt y){if (x.y==y.y) return x.x<y.x;return x.y<y.y;}void addedge(int u,int v,int w){    e[++nume].v=v;    e[nume].w=w;    e[nume].nxt=g[u];    g[u]=nume;}void spfa(int x){    while (!q.empty()) q.pop();    for (int i=1;i<=2*cnt;i++) vis[i]=false,dis[i]=inf;    vis[x]=true;q.push(x);dis[x]=0;    while (!q.empty())    {        int head=q.front();q.pop();        for (int i=g[head];i;i=e[i].nxt)        {            int v=e[i].v;            if (dis[v]>dis[head]+e[i].w)            {                dis[v]=dis[head]+e[i].w;                if (!vis[v]) {vis[v]=true;q.push(v);}            }        }        vis[head]=false;    }}int main(){    scanf("%d%d",&m,&n);    for (int i=1;i<=n;i++)    {        scanf("%d%d",&x,&y);        addpnt(x,y);    }    scanf("%d%d",&x,&y);addpnt(x,y);    scanf("%d%d",&x,&y);addpnt(x,y);    sort(p+1,p+cnt+1,cmp1);    for (int i=1;i<=cnt-1;i++)    {        if (p[i].x==p[i+1].x)        {            addedge(p[i].id,p[i+1].id,(p[i+1].y-p[i].y)<<1);            addedge(p[i+1].id,p[i].id,(p[i+1].y-p[i].y)<<1);        }    }    sort(p+1,p+cnt+1,cmp2);    for (int i=1;i<=cnt-1;i++)    {        if (p[i].y==p[i+1].y)        {            addedge(p[i].id+cnt,p[i+1].id+cnt,(p[i+1].x-p[i].x)<<1);            addedge(p[i+1].id+cnt,p[i].id+cnt,(p[i+1].x-p[i].x)<<1);        }    }    for (int i=1;i<=n;i++)    {        addedge(i,i+cnt,1);        addedge(i+cnt,i,1);    }    spfa(n+1);ans=min(ans,dis[n+2]);ans=min(ans,dis[n+2+cnt]);    spfa(n+1+cnt);ans=min(ans,dis[n+2]);ans=min(ans,dis[n+2+cnt]);    if (ans==inf) printf("-1\n");    else printf("%d\n",ans);    return 0;}