import sequtils

proc getchar_unlocked():char {. importc:"getchar_unlocked",header: "<stdio.h>" .}
proc scan(): int =
  while true:
    let k = getchar_unlocked()
    if k < '0': break
    result = 10 * result + k.ord - '0'.ord

let h = scan()
let w = scan()
var isWater : array[3001,array[3001,bool]]
for y in 0..<h:
  for x in 0..<w:
    isWater[x][y] = getchar_unlocked() == '1'
    discard getchar_unlocked()
var checked : array[3001,array[3001,bool]]
proc check(x,y:int) : bool =
  if checked[x][y] : return false
  if not isWater[x][y]: return false
  checked[x][y] = true
  const dxdy4 :seq[tuple[x,y:int]] = @[(0,1),(1,0),(0,-1),(-1,0)]
  for d in dxdy4:
    let (nx,ny) = (x+d.x,y+d.y)
    if nx < 0 or nx >= w : continue
    if ny < 0 or ny >= h : continue
    if checked[nx][ny] : continue
    if not isWater[nx][ny] : continue
    discard check(nx,ny)
  return true
var ans = 0
for x in 0..<w:
  for y in 0..<h:
    if check(x,y) : ans += 1
echo ans