$1 = 0
while($1 <= W * H)
  $11 = $1//H + 1
  $12 = $1%H + 1
  $3 = A[$11,$12]
  $4 = B[$11,$12]
  $5 = $3 - $4
  $6 = $5 - 1
  $7 = $5 // $6
  $10 = $10 + $7 * $1
  $1 = $1 + 1
end
$12 = $10%H + 1
$11 = $10//H + 1
return ($11,$12)