H, W = gets.split.map(&:to_i)
A = H.times.map { gets.split.map(&:to_i) }
DY = [-1, 0, 1, 0]
DX = [0, 1, 0, -1]

def f(y, x)
  return if A[y][x] == 0
  A[y][x] = 0

  4.times do |i|
    ny = y + DY[i]
    nx = x + DX[i]
    next if ny < 0 || nx < 0 || H <= ny || W <= nx
    next if A[ny][nx] == 0

    f(ny, nx)
  end
end

ans = 0

H.times do |y|
  W.times do |x|
    next if A[y][x] == 0

    ans += 1
    f(y, x)
  end
end

puts ans