H, W = gets.split.map &:to_i
board = $<.map{|s|s.split.join.to_i(2)}
used = H.times.map{[false] * W}

DIRS = [[0, 1], [0, -1], [1, 0], [-1, 0]]

f = ->y, x{
  return if !y.between?(0, H-1)
  return if !x.between?(0, W-1)
  return if board[y][x] == 0
  return if used[y][x]
  used[y][x] = true
  DIRS.each{|dy, dx|
    f[y+dy, x+dx]
  }
}

ans = 0
H.times{|i|
  W.times{|j|
    next if board[i][j] == 0
    next if used[i][j]
    ans += 1
    f[i, j]
  }
}
p ans