#include <iostream>
#include <cstdlib>
using namespace std;

int main()
{
	const size_t ncols = 3;

	char a[][ncols] = {		//can omit only the leftmost dimension
		{'O', 'O', 'X'},	//curly braces optional on this line
		{'X', 'X', 'X'},
		{'O', ' ', 'O'}
	};
	const size_t nrows = sizeof a / sizeof a[0];

	/*
	Each subscript has its own pair of square brackets.
	The first subscript is the row number.
	The second subscript is the column number.
	*/

	cout
		<< a[0][0] << a[0][1] << a[0][2] << "\n"   //top row is row 0
		<< a[1][0] << a[1][1] << a[1][2] << "\n"   //middle row is row 1
		<< a[2][0] << a[2][1] << a[2][2] << "\n\n";//bottom row is row 2

	for (size_t row = 0; row < nrows; ++row) {
		for (size_t col = 0; col < ncols; ++col) {
			cout << a[row][col];
		}
		cout << "\n";
	}

	return EXIT_SUCCESS;
}