#include <bits/stdc++.h>
using namespace std;
using lli = long long;
using lld = long double;
using ulli = unsigned long long int;
using pll = pair<lli, lli>;
using ttt = pair<lli, pll>;
using vttt = vector<ttt>;
using vll = vector<pll>;
using vl = vector<lli>;
using vi = vector<int>;
using vvi = vector<vector<int>>;
using cd = complex<lld>;
void sanjeev(int kkkk) {
  int t;
  cin >> t;
  while (t > 0) {
    t--;
    long long int a, b, x, y;
    cin >> a >> b >> x >> y;
    long long int n;
    cin >> n;
    long long int sa = min(n, a - x);
    long long int sb = min(n, b - y);
    if (a - sa < b - sb) {
      a -= sa;
      n -= sa;
      sb = min(n, b - y);
      b -= sb;
      cout << a * b << '\n';
    } else {
      b -= sb;
      n -= sb;
      sa = min(n, a - x);
      a -= sa;
      cout << a * b << '\n';
    }
  }
}
int main() {
  if (!0) ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  cout << fixed << setprecision(10);
  int t = 1;
  for (int i = 0; i < t; i++) {
    sanjeev(i + 1);
  }
  if (0) system("pause");
}
