$1 = H
$2 = W
$3 = 0
$4 = $1 * $2 
$5 = 0
$6 = 0
while($3 < $4)
  $7 = $3 / $2 + 1
  $8 = $3 % $2 + 1
  $9 = A[$7,$8] - B[$7,$8]
  $10 = ($9 + 4999) / 5000
  $11 = $9 / 5000 
  $11 = 0 - $11
  $5 = $5 + $11 * $7 + $10 * $7
  $6 = $6 + $11 * $8 + $10 * $8
  $3 = $3 + 1
end
return($5,$6)