#include<iostream>
#include<cstdio>
#include<vector>
#include<algorithm>
#define N 3000
using namespace std;
int read()
{
	char c=0;
	int sum=0;
	while (c<'0'||c>'9') c=getchar();
	while ('0'<=c&&c<='9') sum=sum*10+c-'0',c=getchar();
	return sum;
}
int T,n;
long long A,B,a[N+1],b[N+1];
__int128 ans;
struct points
{
	long long x,y;
	bool operator < (const points &t)const
	{
		return x!=t.x?x>t.x:y>t.y;
	}
};
vector<points>solve(vector<points>p)
{
	long long sr=-1;
	vector<points>st;
	sort(p.begin(),p.end());
	for (int i=0;i<p.size();++i)
		if (p[i].y>sr)
			sr=p[i].y,st.push_back(p[i]);
	return st;
}
void write(__int128 x)
{
	if (!x) return;
	write(x/10),printf("%d",(int)(x%10));
	return;
}
int main()
{
	vector<points>p;
	vector<points>st;
	T=read(),n=read(),A=read(),B=read();
	while (T--)
	{
		p.clear(),p.push_back((points){0,0}),ans=0;
		for (int i=1;i<=n;++i)
		{
			st.clear(),a[i]=read(),b[i]=read();
			for (int j=0;j<p.size();++j) st.push_back((points){p[j].x+a[i],p[j].y}),st.push_back((points){p[j].x,p[j].y+b[i]});
			p=solve(st);
		}
		for (int i=0;i<p.size();++i) ans=max(ans,(__int128)(p[i].x)*p[i].y);
	    write(ans),puts("");
	}
	return 0;
}