#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
//using mint = modint998244353;
//const int mod = 998244353;
//using mint = modint1000000007;
//const int mod = 1000000007;
const int INF = 1e9;
//const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n-1); i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int t; cin >> t;
	while (t--) {
		int n, m; cin >> n >> m;
		vector<int>l(n), r(n);
		rep(i, n)cin >> l[i];
		rep(i, n)cin >> r[i];
		if (!(accumulate(all(l), 0LL) <= m && m <= accumulate(all(r), 0LL))) {
			cout << -1 << endl;
			continue;
		}
		int lb = 0, ub = 1000000001;
		while (ub - lb > 1) {
			int c = (ub + lb) / 2;
			long long cnt = 0;
			rep(i, n) cnt += clamp(c, l[i], r[i]);
			(cnt <= m ? lb : ub) = c;
		}
		vector<int>a(n);
		rep(i, n) a[i] = clamp(lb, l[i], r[i]);
		int x = m - accumulate(all(a), 0);
		rep(i, n) {
			if (x > 0 && l[i] <= lb && lb < r[i]) {
				a[i]++;
				x--;
			}
		}
		long long ans = 0;
		rep(i, n) ans += ((long long)m - a[i]) * a[i];
		ans /= 2;
		cout << ans << endl;
	}
	return 0;
}