#include <bits/stdc++.h>
using namespace std;
const int INF = 1e9 + 7;
const int MOD = 1e9 + 7;
const int di[4] = {1, 0, -1, 0};
const int dj[4] = {0, 1, 0, -1};
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int t;
  cin >> t;
  while (t--) {
    long long a, b, x, y, n;
    cin >> a >> b >> x >> y >> n;
    long long a2, b2, x2, y2, n2;
    a2 = a, b2 = b, x2 = x, y2 = y, n2 = n;
    long long cnt_to_a = a - x;
    long long cnt_to_a2 = cnt_to_a;
    long long cnt_to_b = b - y;
    long long cnt_to_b2 = cnt_to_b;
    if (cnt_to_a < n) {
      a = x;
      n -= cnt_to_a;
    } else {
      a -= n;
      n = 0;
    }
    if (cnt_to_b < n) {
      b = y;
      n -= cnt_to_b;
    } else {
      b -= n;
      n = 0;
    }
    if (cnt_to_b2 < n2) {
      b2 = y2;
      n2 -= cnt_to_b2;
    } else {
      b2 -= n2;
      n2 = 0;
    }
    if (cnt_to_a2 < n2) {
      a2 = x2;
      n2 -= cnt_to_a2;
    } else {
      a2 -= n2;
      n2 = 0;
    }
    cout << min(a * b, a2 * b2) << endl;
  }
}
