#include<bits/stdc++.h>
using namespace std;
const int N =3030;
typedef long long LL;
#define BIG __int128
int n;
LL Ra,Rb;
LL a[N],b[N];
mt19937 rnd(time(0));
int Make(int l,int r)
{
	return rnd()%(r-l+1)+l;
}
void print(BIG x)
{
	if(x>9)print(x/10);
	putchar('0'+x%10);
}
BIG A=0,B=0,C=0;
int state[N];
const int LIM = 50000;
const int K = 2;
int p[N];
void solve()
{
	for(int i=1;i<=n;i++)scanf("%lld %lld",&a[i],&b[i]);
	A=0;B=0;C=0;
	for(int ip=1;ip<=20;ip++)
	{
		A=0;B=0;
		for(int i=1;i<=n;i++)
		{
			state[i]=Make(0,1);
			if(state[i]==0)A+=a[i];
			else B+=b[i];
		}
		for(int o=1;o<=LIM;o++)
		{
			int k=0;
			int L=Make(1,K);
			for(int i=1;i<=L;i++)p[++k]=Make(1,n);sort(p+1,p+k+1);k=unique(p+1,p+k+1)-p-1;
			BIG nA=A,nB=B;
			for(int i=1;i<=k;i++)
			{
				int x=p[i];
				if(state[x]==0)nA-=a[x],nB+=b[x];
				else nA+=a[x],nB-=b[x];
			}
			if(nA*nB>C)
			{
				C=nA*nB;A=nA;B=nB;
				for(int i=1;i<=k;i++)
				state[p[i]]^=1;
			}
		}
	}
	print(C);
	putchar('\n');
}
int main() 
{
	int T;
	scanf("%d %d %lld %lld",&T,&n,&Ra,&Rb);
	while(T--)
	{
		solve();
	}
	return 0;
}