grid = ARGF.read.chars
length = grid.find_index ?\n

puts grid.each_with_index.count { |item, i|
  item == ?@ && [-length-2, -length-1, -length, -1, 1, length, length+1, length+2].count { i + _1 > 0 && grid[i + _1] == ?@ } < 4
}