#include <bits/stdc++.h>
using namespace std;
int main() {
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    int a[n];
    for (int i = 0; i < n; ++i) {
      cin >> a[i];
    }
    for (int i = n - 1; i >= 0; --i) {
      int temp = i % 2 != 0 ? -a[i] : a[i];
      cout << temp << " ";
    }
    cout << endl;
  }
}
