#include <bits/stdc++.h>
#ifdef LOCAL
#include <debug.hpp>
#else
#define debug(...) void(0)
#endif

using namespace std;

typedef long long ll;
#define all(x) begin(x), end(x)
constexpr int INF = (1 << 30) - 1;
constexpr long long IINF = (1LL << 60) - 1;
constexpr int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};

template <class T> istream& operator>>(istream& is, vector<T>& v) {
    for (auto& x : v) is >> x;
    return is;
}

template <class T> ostream& operator<<(ostream& os, const vector<T>& v) {
    auto sep = "";
    for (const auto& x : v) os << exchange(sep, " ") << x;
    return os;
}

template <class T, class U = T> bool chmin(T& x, U&& y) { return y < x and (x = forward<U>(y), true); }

template <class T, class U = T> bool chmax(T& x, U&& y) { return x < y and (x = forward<U>(y), true); }

template <class T> void mkuni(vector<T>& v) {
    sort(begin(v), end(v));
    v.erase(unique(begin(v), end(v)), end(v));
}

template <class T> int lwb(const vector<T>& v, const T& x) { return lower_bound(begin(v), end(v), x) - begin(v); }

void solve() {
    int n;
    ll m;
    cin >> n >> m;
    vector<ll> L(n), R(n);
    cin >> L >> R;

    reverse(all(L));
    reverse(all(R));
    ll LS = accumulate(all(L), 0LL), RS = accumulate(all(R), 0LL);
    if (not(LS <= m and m <= RS)) {
        cout << -1 << '\n';
        return;
    }
    auto calc = [&](ll x) -> ll {
        ll res = 0;
        for (int i = 0; i < n; i++) {
            if (x <= L[i]) continue;
            res += min(x, R[i]) - L[i];
        }
        return res;
    };
    ll lb = 0, ub = INF;
    while (ub - lb > 1) {
        ll mid = (ub + lb) >> 1;
        (calc(mid) <= m - LS ? lb : ub) = mid;
    }
    ll target = lb;
    vector<ll> cur(n);
    vector<pair<ll, int>> v;
    for (int i = 0; i < n; i++) {
        if (target <= L[i])
            cur[i] = L[i];
        else
            cur[i] = min(target, R[i]);
        if (cur[i] < R[i]) v.emplace_back(cur[i], i);
    }
    LS = accumulate(all(cur), 0LL);
    sort(all(v));
    for (int i = 0; i < m - LS and i < int(v.size()); i++) cur[v[i].second]++;

    ll ans = 0;
    for (int i = 0; i < n; i++) ans += cur[i] * cur[i];
    ans = (m * m - ans) / 2;
    cout << ans << '\n';
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int T;
    cin >> T;
    for (; T--;) solve();
    return 0;
}