$0 = H * W
$1 = 0
$4 = 0
$5 = 0
while($1 < $0)
  $2 = $1 / W + 1
  $3 = $1 % W + 1
  $6 = A[$2,$3] - B[$2,$3]
  $4 = $4 + $6
  $5 = $5 + $6 * $1
  $1 = $1 + 1
end
$1 = $5 / $4
$2 = $1 / W + 1
$3 = $1 % W + 1
return($2,$3)