#!/usr/bin/perl

use strict;

my $dimension = shift || 4;

my @card_matrix = (1 .. $dimension ** 2);

print_matrix(@card_matrix);
print "\nrow? : "; my $row = <STDIN>; chomp($row);

print_matrix(reverse @card_matrix);
print "\ncol? : "; my $col = <STDIN>; chomp($col);

print "\nsolution: ", 
	$card_matrix[($row - 1) * $dimension + ($dimension - $col)];


sub print_matrix
{
  my @matrix = @_;
	
  my $dimension = sqrt(@matrix);
	
  printf "\n" . "\t[%d]" x $dimension, (1..$dimension);
		
    for(my $row = 0; $row < $dimension; $row++)
    {
      printf "\n[%d]" . "\t%d" x $dimension, 
             $row + 1, @matrix[$row * $dimension .. $row * $dimension + $dimension - 1];
    }
}