#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic warning "-Wunused-function"
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int tt;
  cin >> tt;
  while(tt--) {
    int n, m;
    cin >> n >> m;
    VI 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 << '\n';
      continue;
    }
    int lb = 0, ub = 1000000001;
    while(ub - lb > 1) {
      int c = (ub + lb) / 2;
      ll cnt = 0;
      rep(i, n) cnt += clamp(c, l[i], r[i]);
      (cnt <= m ? lb : ub) = c;
    }
    VI dist(n);
    rep(i, n) dist[i] = clamp(lb, l[i], r[i]);
    int rest = m - accumulate(all(dist), 0);
    rep(i, n) if (rest && l[i] <= lb && lb < r[i]) {
      dist[i]++;
      rest--;
    }
    assert(rest == 0);
    ll ans = 0;
    rep(i, n) ans += ll(m - dist[i]) * dist[i];
    ans /= 2;
    cout << ans << '\n';
  }
}