#include <bits/stdc++.h>
using namespace std;
 
#define int long long
void solve(){
	int n,k,a,b;
	cin>>n>>k>>a>>b;
	--k;
	--a,--b;
	vector<pair<int,int>> v(n);
	for(int i=0;i<n;i++){
		int x,y;
		cin>>x>>y;
		v[i]={x,y};
	}
		int x1=v[a].first,y1=v[a].second;
	int x2=v[b].first,y2=v[b].second;
	int d=abs(x1-x2)+abs(y1-y2);
 
	if(k<0){
		cout<<d<<endl;
		return ;
	}
	if(a>k && b<=k){
		for(int i=0;i<=k;i++){
			d=min(d,abs(x1-v[i].first)+abs(y1-v[i].second));
		}
	}
	if(a<=k && b>k){
		for(int i=0;i<=k;i++){
			d=min(d,abs(x2-v[i].first)+abs(y2-v[i].second));
		}
	}
	if(a>k && b>k){
		int d1=1e12;
		for(int i=0;i<=k;i++){
			d1=min(d1,abs(x1-v[i].first)+abs(y1-v[i].second));
		}
		int d2=1e12;
		for(int i=0;i<=k;i++){
			d2=min(d2,abs(x2-v[i].first)+abs(y2-v[i].second));
		}
		d=min(d,d1+d2);
	}
	else if(a<=k && b<=k){
		cout<<0<<endl;
		return;
 
	}
 
		cout<<d<<endl;	
 
 
 
 
}
signed main() {
	// your code goes here
	int t;
	cin>>t;
	while(t--){
		solve();
	}
	return 0;
}

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5
6 2 3 5
0 0
1 -2
-2 1
-1 3
2 -2
-3 -3
2 0 1 2
-1000000000 -1000000000
1000000000 1000000000
7 5 4 2
154 147
-154 -147
123 456
20 23
43 20
998 244
353 100
3 1 3 1
0 10
1 20
2 30
4 3 2 4
0 0
-100 100
-1 -1
-1 0