1589B - Coloring Rectangles - CodeForces Solution

//============================================================================
// Name        : Problem_Solving.cpp
// Author      : Aya_Gamal
//============================================================================

#include <iostream>
#include <algorithm>
#include <cmath>
#include <string>
#include <array>
#include <climits>
#include <cstdlib>
#include <iomanip>
#include <ctime>
#include <vector>
#include <deque>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <functional>
#include <numeric>
#include <utility>
#include <string.h>
#include <cstdint>
using namespace std;

#define HeartAttack ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define ll long long
#define oo 1e9
#define forr(i,n) for(int i=0; i < n; i++)

int main() {
    HeartAttack
	int t; cin>>t;

	while(t--){
    ll n, m;
    cin >> n >> m;
    cout<< ((n*m)/3)+ ((n*m)%3 != 0)<<"\n";
  
 }


    return 0;
}//