Snake's Neck

#include<bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define ll int
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    ll i,j,a,b,n,m;

    cin>>n;

    vector<pair<ll,ll> >v;

    map<pair<ll,ll>,ll>mp;


    for(i=1; i<=n; i++)
    {
        cin>>a>>b;

        v.emplace_back(a,b);
    }
    cin>>m;

    for(i=1; i<=m; i++)
    {
        cin>>a>>b;

        mp[{a,b}]=i;
    }

   ll pre,pos,ans=0;
   i=0;
    while(i<n)
    {
        if(mp[{v[i].F,v[i].S}])
        {


            pre=mp[{v[i].F,v[i].S}];

            i++;

            ll cnt=1;


            while(i<n)
            {
                pos=mp[{v[i].F,v[i].S}];


                if(pre+1==pos)
                {
                    cnt++;
                }
                else break;

                pre=pos;

                i++;
            }
            i--;

            ans=max(ans,cnt);
        }
        i++;
    }
    i=0;

    while(i<n)
    {
        if(mp[{v[i].F,v[i].S}])
        {


            pre=mp[{v[i].F,v[i].S}];

            i++;

            ll cnt=1;


            while(i<n)
            {
                pos=mp[{v[i].F,v[i].S}];


                if(pre==pos+1)
                {
                    cnt++;
                }
                else break;

                pre=pos;

                i++;
            }
            i--;

            ans=max(ans,cnt);
        }
        i++;
    }





    cout<<ans<<endl;









    return 0;






}