#include<bits/stdc++.h>
#define ll long long
#define i28 __int128
#define pii pair<ll,ll>
#define fi first
#define se second
#define pb push_back
#define mp make_pair
using namespace std;
int n;ll a[3030],b[3030];
vector<pii>vec,v1,v2;
int ps[6030],tt;
mt19937 rnd(time(0));
void solve(){
	vec.clear(),vec.pb(mp(0,0));
	ll s=0;
	for(int i=1;i<=n;++i){
		scanf("%lld%lld",&a[i],&b[i]),s+=a[i],v1=vec,v2.clear();
		for(auto v:vec)v2.pb(mp(v.fi+b[i],v.se+a[i]));vec.clear();
		int p=0,q=0;
		while(p<v1.size()&&q<v2.size()){
			if(v1[p]<v2[q])vec.pb(v1[p++]);
			else vec.pb(v2[q++]);
		}
		while(p<v1.size())vec.pb(v1[p++]);
		while(q<v2.size())vec.pb(v2[q++]);
		ll mx=-1e18;
		v1.clear();
		for(auto v:vec){
			if(v.se<=mx)continue;
			mx=v.se,v1.pb(v);
		}
		vec=v1;tt=vec.size();
		for(int j=1;j<=tt;++j)ps[j]=j;
		shuffle(ps+1,ps+tt+1,rnd);
		if(tt>3000){
			v1.clear();
			for(int j=1;j<=3000;++j)v1.pb(vec[ps[j]-1]);
			vec=v1;
		}
	}
	i28 ans=0;
	for(auto v:vec)ans=max(ans,(i28)v.fi*(i28)(s-v.se));
    stack<char>stk;while(stk.size())stk.pop();
    while(ans)stk.push((char)(ans%(i28)(10)+'0')),ans/=(i28)(10);
    while(stk.size())putchar(stk.top()),stk.pop();
    puts("");
}
int main(){
	ll ta,tb;
	int t;cin>>t>>n>>ta>>tb;
	while(t--)solve();
	return 0;
}