#include "bits/stdc++.h"
#include <unordered_map>
#include <unordered_set>

#include <stdio.h>
#include <math.h>
#include <cassert>

#include "atcoder/all"
#include <float.h>

//#include <boost/multiprecision/cpp_int.hpp>
//using namespace boost::multiprecision;
// std::fixed << std::setprecision(10) <<

using namespace std;
using namespace atcoder;

using ll = long long;
using ull = unsigned long long;
using mint = modint998244353;
using mint2 = modint1000000007;

const double eps = 1e-9;

#define REP(i, n) for (ll i = 0; i < ll(n); ++i)
#define REPI(i, init, n) for (ll i = init; i < ll(n); ++i)
#define REPD(i, init) for (ll i = init; i >=0; --i)
#define REPDI(i, init, n) for (ll i = init; i >=n; --i)
#define REPE(i, c) for (const auto& i : c)
#define TCASE() ll _ttt; cin >> _ttt; while(_ttt--)

using vl = vector<ll>;
#define VL(a, n) vector<ll> a; a.assign(n, 0);
#define VLI(a, n) vector<ll> a; a.assign(n, 0); for(auto& x : a) cin >> x;
#define VSI(a, n) vector<string> a; a.assign(n, ""); for(auto& x : a) cin >> x;
using vvl = vector<vector<ll>>;
#define VVLI(a, n, m, init) vector<vector<ll>> a(n); for(auto& x : a) x.assign(m, init);
using vd = vector<double>;
using pl = pair<ll, ll>;

struct uv { ll u; ll v; ll c; };
#define VUVI(a, n) vector<uv> a; a.assign(n, {0, 0, 1}); for(auto& x : a) {cin >> x.u >> x.v; x.u--; x.v--;}
#define VUVCI(a, n) vector<uv> a; a.assign(n, {0, 0, 0}); for(auto& x : a) {cin >> x.u >> x.v >> x.c; x.u--; x.v--;}
vvl to_edge(const ll n, const vector<uv>& v) { vvl ret(n); for (auto& x : v) ret[x.u].push_back(x.v); return ret; }
vvl to_edge_d(const ll n, const vector<uv>& v) { vvl ret(n); for (auto& x : v) { ret[x.u].push_back(x.v); ret[x.v].push_back(x.u); } return ret; }

template <class T = long long> using pql = priority_queue<T>;
template <class T = long long> using pqg = priority_queue<T, vector<T>, greater<T>>;
using vm = vector<mint>;
using vvm = vector<vm>;

void yn(bool f) { std::cout << (f ? "Yes" : "No") << endl; };
template<class T> void ov(const T& v) { for (auto it = v.begin(); it != v.end(); it++) { if (it != v.begin()) cout << " "; cout << *it; } };
template<> void ov(const vm& v) { for (auto it = v.begin(); it != v.end(); it++) { if (it != v.begin()) cout << " "; cout << it->val(); } };

const ll llhuge = 1LL << 60; //十分でかいが多少足しても溢れない数値
auto gmax(const auto& a, const auto& b) { return a > b ? a : b; };
auto gmin(const auto& a, const auto& b) { return a < b ? a : b; };
template<class T, class U> bool chmin(T& a, const U& b) { const T olda = a; a = gmin(a, b); return olda != a; }
template<class T, class U> bool chmax(T& a, const U& b) { const T olda = a; a = gmax(a, b); return olda != a; }
template<class T> void mysort(T& v) { std::sort(begin(v), end(v)); };
template<class T, class U> void mysort(T& v, U pr) { std::sort(begin(v), end(v), pr); };
template<class T> void myrev(T& v) { std::reverse(begin(v), end(v)); };


//二分探索でf(t)を満たす整数tを返す
//ng < ok ならtは最小値 ng > ok ならtは最大値
template <class F>
ll bs(ll ng, ll ok, F f) {
	while (abs(ok - ng) > 1) {
		ll mid = (ok + ng) / 2;

		if (f(mid)) ok = mid;
		else ng = mid;
	}
	return ok;
}

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


	TCASE() {
		ll n, m;
		cin >> n >> m;

		VLI(l, n);
		VLI(r, n);

		ll lsum = 0;
		ll rsum = 0;
		REP(i, n) {
			lsum += l[i];
			rsum += r[i];
		}

		if (lsum > m || rsum < m) {
			cout << -1 << endl;
			continue;
		}

		//全ての要素が可能なら満たす数字を調べる
		ll tv = bs(m + 1, 0, [&](ll t) {
			ll sum = 0;
			REP(i, n) {
				ll add = t;
				if (r[i] < t) add = r[i];
				if (l[i] > t) add = l[i];
				sum += add;
			}
			return sum <= m;
		});

		//全ての要素を弄ってしまう。
		vl tl = l;
		REP(i, n) {
			if (r[i] < tv) tl[i] = r[i];
			else tl[i] = tv;

			m -= tl[i];
		}

		//mの残りは大きいほうから1ずつ足せれば足す
		REPD(i, n-1) {
			if (m <= 0) break;
			if (tl[i] < r[i]) {
				tl[i]++;
				m--;
			}
		}

		//転倒数を数える
		ll ans = 0;
		ll revt = 0;
		REP(i, n) {
			ans += revt * tl[i];
			revt += tl[i];
		}

		cout << ans << endl;
	}
}