#include <bits/stdc++.h>
using namespace std;
#define For(Ti,Ta,Tb) for(auto Ti=(Ta);Ti<=(Tb);++Ti)
#define Dec(Ti,Ta,Tb) for(auto Ti=(Ta);Ti>=(Tb);--Ti)
#define debug(...) fprintf(stderr,__VA_ARGS__)
#define range(Tx) begin(Tx),end(Tx)
using ll=long long;
using i128=__int128;
ostream& operator<<(ostream& os,i128 x){
	if(x>=10) os<<x/10;
	return os<<int(x%10);
}
const int N=3005;
int T,n,sel[N];
ll A,B;
struct Node{
	ll a,b;
}p[N];
int main(){
	cin.tie(nullptr)->sync_with_stdio(false);
	cin>>T>>n>>A>>B;
	while(T--){
		For(i,1,n){
			cin>>p[i].a>>p[i].b;
		}
		sort(p+1,p+n+1,[](Node n1,Node n2){
			return i128(n1.b)*n2.a<i128(n2.b)*n1.a;
		});
		ll sa=0,sb=0;
		i128 ans=0;
		For(i,1,n) sb+=p[i].b;
		auto change=[&](int i){
			if(!sel[i]){
				sa+=p[i].a;
				sb-=p[i].b;
			}else{
				sa-=p[i].a;
				sb+=p[i].b;
			}
			sel[i]^=1;
			ans=max(ans,i128(sa)*sb);
		};
		For(i,1,n){
			change(i);
			For(j,max(1,i-10),min(n,i+10)){
				change(j);
				change(j);
			}
		}
		cout<<ans<<'\n';
		For(i,1,n) sel[i]=0;
	}
	return 0;
}