1010-Knights-In-Chessboard.cpp

#include <iostream>
#include <stdio.h>
using namespace std;

int cal(int row, int col)
{
	int col1;
	int col2;
	int row1;
	int row2;
	int ans;

	int temp;

	

	row1 = (row / 2) + (row % 2);
	row2 = (row / 2);

	col1 = (col / 2) + (col % 2);
	col2 = col / 2;

	ans = row1 * col1 + row2 * col2;


	return ans;

}


int two(int row, int col)
{
	int ans;
	int temp;

	temp = cal(row, col);

	row = max(row, col);

	ans = (row / 4) * 4 + min(2, row % 4) * 2;

	ans = max(ans, temp);

	return ans;

}

int main()
{

	int t;

	int row;
	int col;
	scanf("%d", &t);

	for (int cs = 1; cs <= t; cs++) {
		scanf("%d", &row);
		scanf("%d", &col);


		if(row == 1 or col == 1) {
			
			printf("Case %d: %d\n", cs, max(row, col));
			continue;
		
		}

		if(row == 2 or col == 2) {
			printf("Case %d: %d\n", cs, two(row, col));
			continue;
		}

		if(min(row, col) == 2 and max(row, col) == 3) {

			printf("Case %d: 4\n", cs);
			continue;
		}


		printf("Case %d: %d\n", cs, cal(row, col));

	}


}