#include <bits/stdc++.h>
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
void c_p_c() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
}
long long int gcd(long long int a, long long int b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
bool is_pallindrome(string str, long long int left, long long int right) {
  if (left > right) return true;
  return (str[left] == str[right] && is_pallindrome(str, left + 1, right - 1));
}
long long int convertToInt(string str) {
  long long int sum = 0;
  long long int power = 1;
  for (long long int i = str.length() - 1; i >= 0; i--) {
    long long int val = str[i] - '0';
    long long int prod =
        ((val % 1000000007) * (power % 1000000007)) % 1000000007;
    sum = ((sum % 1000000007) + prod % 1000000007) % 1000000007;
    power *= 10;
  }
  return sum;
}
bool compare(pair<long long int, long long int> a,
             pair<long long int, long long int> b) {
  if (a.first != b.first) return a.first < b.first;
  return a.second < b.second;
}
int32_t main() {
  c_p_c();
  long long int t;
  cin >> t;
  while (t--) {
    long long int a, b;
    cin >> a >> b;
    if (b % 2 == 0) {
      cout << a * (b / 2);
    } else {
      long long int ans = b / 2 * a;
      if (a % 2 == 0)
        ans += a / 2;
      else
        ans += (a / 2) + 1;
      cout << ans;
    }
    cout << "\n";
  }
  return 0;
}
