B

#include <bits/stdc++.h>

using namespace std;

#define ll     long long
#define _test   int _TEST; cin>>_TEST; while(_TEST--)
#define pb     push_back
#define ff     first
#define ss     second

int main()
{
    _test
    {
        int n, k, a, b;
        cin>>n>>k>>a>>b;

        vector<pair<int, int>> vp(n);
        for(auto &[a, b]: vp)
            cin>>a>>b;

        a--, b--;

        ll int ans = fabs(vp[a].ff - vp[b].ff) + fabs(vp[a].ss - vp[b].ss);

        vector<ll int> cst(k);
        ll int mmin = 1e18;

        for(int i=0; i<k; i++)
        {
            cst[i] = fabs(vp[a].ff - vp[i].ff) + fabs(vp[a].ss - vp[i].ss);
            mmin = min(mmin, (ll)(fabs(vp[i].ff - vp[b].ff) + fabs(vp[i].ss - vp[b].ss)));
        }

        if(cst.size() > 0)      ans = min(ans, *min_element(cst.begin(), cst.end()) + mmin);

        cout<<ans<<"\n";
    }
}