#include <cstdio>
#include <random>
#include <algorithm>
#define int long long

using std::min; using std::max;
typedef __int128 lll;
int n;
void write(lll x) {
    char ch[105]; int top = 0;
    while (x) ch[++ top] = x % 10 + '0', x /= 10;
    while (top) putchar(ch[top --]);
}
struct node {
    int a, b;
    inline bool operator < (const node &rhs) const {return (lll)a * rhs.b < (lll)rhs.a * b;}
} a[3005];
int preb[3005], sufa[3005];

signed main() {
    int _; scanf("%lld%lld%*d%*d", &_, &n);
    while (_ --) {
        lll ans = 0;
        for (int i = 1; i <= n; ++ i) scanf("%lld%lld", &a[i].a, &a[i].b);
        std::sort(a + 1, a + n + 1);
        for (int i = 1; i <= n; ++ i) preb[i] = preb[i - 1] + a[i].b;
        sufa[n + 1] = 0;
        for (int i = n; i; -- i) sufa[i] = sufa[i + 1] + a[i].a;
        if (n <= 300)
            for (int i = 1; i <= n; ++ i) {
                int l = max(1ll, i - 5), r = min(n, i + 5);//before l b after r a
                int len = r - l + 1; int sa = sufa[r + 1], sb = preb[l - 1];
                for (int S = 0; S < 1 << len; ++ S) {
                    int ta = sa, tb = sb;
                    for (int j = 0; j < len; ++ j)
                        if (S & 1 << j) ta += a[j + l].a;
                        else tb += a[j + l].b;
                    if ((lll)ta * tb > ans) ans = (lll)ta * tb;
            }
        } else {
            for (int i = n / 2 - 100; i <= n / 2 + 100; ++ i) {
                int l = max(1ll, i - 5), r = min(n, i + 5);//before l b after r a
                int len = r - l + 1; int sa = sufa[r + 1], sb = preb[l - 1];
                for (int S = 0; S < 1 << len; ++ S) {
                    int ta = sa, tb = sb;
                    for (int j = 0; j < len; ++ j)
                        if (S & 1 << j) ta += a[j + l].a;
                        else tb += a[j + l].b;
                    if ((lll)ta * tb > ans) ans = (lll)ta * tb;
            }
        }
        }
        write(ans), putchar('\n');
    }
    return 0;
}