#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#ifdef Local
#include "debug/debug.h"
#else
#define debug(...)
#endif

typedef long long ll;
typedef long double ld;

#define int ll

#define vec vector
#define str string
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define rev(x) reverse(x)
#define sz(x) (int)(x).size()
#define pb push_back

using namespace std;
using namespace __gnu_pbds;

void solve() {
    int n, q;
    cin >> n >> q;
    vec<int> a(n);
    gp_hash_table<int, int> cnt;
    for (int& i : a) {
        cin >> i;
        cnt[i]++;
    }
    gp_hash_table<int, vec<int>> c;
    for (auto& [k, i] : cnt) {
        c[i].pb(k);
    }
    for (auto& [k, i] : c) {
        sort(rall(i));
    }
    gp_hash_table<int, int> qs;
    auto h = [&](int& a, int& b) { return min(a, b) << 30 | max(a, b); };
    for (int i = 0, x, y; i < q; i++) {
        cin >> x >> y;
        qs[h(x, y)] = 1;
    }
    int ans = 0;
    for (int i = 0; i < sz(a); i++) {
        int x = a[i], g = cnt[x];
        for (auto& [k, j] : c) {
            if (k < g)
                continue;
            for (int& y : j) {
                if (x != y && qs.find(h(x, y)) == qs.end()) {
                    ans = max(ans, (cnt[x] + cnt[y]) * (x + y));
                    break;
                }
            }
        }
    }
    cout << ans << '\n';
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int tt = 1;
    cin >> tt;
    while (tt--)
        solve();

    return 0;
}