Go: ///
// File:  1160.go
// Author: ymiyamoto
//
// Created on Sun Mar  4 20:45:57 2018
//
package main

import (
	"fmt"
)

var w, h int
var graph [][]string

func dfs(visited [][]bool, x, y int) {
	visited[x][y] = true

	for i := -1; i <= 1; i++ {
		for j := -1; j <= 1; j++ {
			dx := x + i
			dy := y + j
			if 0 <= dx && dx < h && 0 <= dy && dy < w && graph[dx][dy] == "1" && !visited[dx][dy] {
				dfs(visited, dx, dy)
			}
		}
	}
}

func main() {
	for {
		fmt.Scan(&w, &h)
		if w == 0 && h == 0 {
			break
		}

		graph = make([][]string, h)
		for i := range graph {
			graph[i] = make([]string, w)
		}

		for i := 0; i < h; i++ {
			for j := 0; j < w; j++ {
				var s string
				fmt.Scan(&s)
				graph[i][j] = s
			}
		}

		visited := make([][]bool, h)
		for i := range visited {
			visited[i] = make([]bool, w)
		}

		count := 0
		for i := range graph {
			for j := range graph[i] {
				if graph[i][j] == "1" && !visited[i][j] {
					dfs(visited, i, j)
					count++
				}
			}
		}

		fmt.Println(count)
	}
}

Python: import sys
from collections import deque
sys.setrecursionlimit(10**9)

dx = [1,1,0,-1,-1,-1,0,1]
dy = [0,-1,-1,-1,0,1,1,1]
  
def DFS(y,x):
  if table[y][x] == 0:
    return
  table[y][x] = 0
  for i in range(8):
    nx = x + dx[i]
    ny = y + dy[i]
    if 0<=ny<h and 0<=nx<w:
      DFS(ny, nx)
while True:  
  w, h = map(int, input().split())
  if w == 0 and h == 0:
    exit()
  table = []
  ans = 0
  for i in range(h):
    c = list(map(int, input().split()))
    table.append(c)
  for y in range(h):
    for x in range(w):
      if table[y][x] == 1:
        ans += 1
        DFS(y,x)
  print(ans)

Python: import sys
sys.setrecursionlimit(5000)

input = sys.stdin.readline
sea_map = []
chk_map = []
h = 0
w = 0
def chk_island(i,j):
    chk_map[i][j] = False
    if sea_map[i][j] == 0:
        return 0
    for d in ((-1,0), (-1,1), (0,1), (1,1), (1,0), (1,-1), (0,-1), (-1,-1)):
        if 0 <= i + d[0] < h and 0 <= j + d[1] < w:
            if chk_map[i+d[0]][j+d[1]]:
                chk_island(i+d[0],j+d[1])
    return 1

while True:
    count = 0
    w, h = map(int,input().split())
    if w == 0 and h == 0:
        break
    sea_map = [list(map(int,input().split())) for _ in range(h)]
    chk_map = [[True for _ in range(w)] for _ in range(h)]

    for i in range(h):
        for j in range(w):
            if chk_map[i][j]:
                count += chk_island(i,j)
    print (count)

Python: import sys
sys.setrecursionlimit(10000)

def dfs(x,y):
	for i in range(8):
		nx=x+dx[i]
		ny=y+dy[i]
		if 0<=nx<h and 0<=ny<w and C[nx][ny]==1 and D[nx][ny]==0:
			D[nx][ny]=d
			dfs(nx,ny)

dx=[1,1,0,-1,-1,-1,0,1]
dy=[0,1,1,1,0,-1,-1,-1]

while True:
	w,h=map(int,input().split())
	if w==0 and h==0:
		exit()
	d=0
	C=[list(map(int,input().split())) for i in range(h)]
	D=[[0]*w for i in range(h)]
	for x in range(h):
		for y in range(w):
			if C[x][y]==1 and D[x][y]==0:
				d+=1
				dfs(x,y)
	print(d)

Python: import sys
sys.setrecursionlimit(500000)

def allblue(H, W, C):
    for h in range(H):
        for w in range(W):
            if C[h][w] == 1:
                return (h, w)
    return (-1, -1)

directions = [(0, 1), (0, -1), (1, 1), (1, 0), (1, -1), (-1, -1), (-1, 0), (-1, 1)]
def dfs(h, w, C):
    C[h][w] = 0
    for dh, dw in directions:
        if 0 <= h+dh < H and 0 <= w+dw < W and C[h+dh][w+dw] == 1:
            dfs(h+dh, w+dw, C)

while True:
    W, H = map(int, input().split())
    if W == 0 and H == 0:
        exit()
    C = [list(map(int, input().split())) for i in range(H)]

    ans = 0
    while True:
        h, w = allblue(H, W, C)
        if (h, w) == (-1, -1):
            break
        dfs(h, w, C)
        ans += 1

    print(ans)

Python: import sys
sys.setrecursionlimit(10000)
def search(x,y,m):
    if not(0<=x<len(m[0]) and 0<=y<len(m)) or m[y][x]=='0': return
    m[y][x] = '0'
    for dx,dy in [[-1,-1],[0,-1],[1,-1],[-1,0],[1,0],[-1,1],[0,1],[1,1]]:
        search(x+dx,y+dy,m)
while True:
    w,h = map(int,input().split())
    if w==h==0: break
    m = [input().split() for _ in range(h)]
    c = 0
    for y in range(h):
        for x in range(w):
            if m[y][x]=='1':
                c += 1
                search(x,y,m)
    print(c)

Python: 
if __name__ == "__main__":
    while True:
        w, h = map(int, input().split())
        if w == 0 and h == 0:
            break
        c = []
        for _ in range(h):
            hi = list(map(int, input().split()))
            c.append(hi)
        
        visited = []
        for _ in range(h):
            hi = [False] * w
            visited.append(hi)
        
        st = []
        ans = 0

        for s_row in range(h):
            for s_col in range(w):
                if c[s_row][s_col] != 0 and not visited[s_row][s_col]:
                    st = [(s_row, s_col)]
                    while st:
                        now = st.pop()
                        for i in range(-1, 2):
                            for j in range(-1, 2):
                                if now[0] + i >= 0 and now[0] + i < h and now[1] + j >= 0 and now[1] + j < w and not visited[now[0] + i][now[1] + j] and c[now[0] + i][now[1] + j] != 0:
                                    visited[now[0] + i][now[1] + j] = True
                                    st.append((now[0] + i, now[1] + j))
                    ans += 1
        print(ans)

Python: import sys
sys.setrecursionlimit(1000000)

while(1):
    w, h = map(int, input().split())
    if w == 0 and h == 0:
        break
    else:
        maps = [[-1]*(w+2)] + [([-1] + list(map(int, input().split())) + [-1]) for _ in range(h)] + [[-1]*(w+2)]
        seen = [[True]*(w+2)] + [([True] + [False]*w + [True]) for _ in range(h)] + [[True]*(w+2)]
        dxy = ((-1, -1), (-1, 0), (-1, 1), (0, -1), (0, 1), (1, -1), (1, 0), (1, 1))
        
        
        def dfs(y, x):
            seen[y][x] = True
            for i in dxy:
                if seen[y+i[0]][x+i[1]] is False:
                    if maps[y+i[0]][x+i[1]] == 0:
                        seen[y+i[0]][x+i[1]] = True
                    else:
                        dfs(y+i[0], x+i[1])
        
        now = 0
        ans = 0
        while now < w * h:
            y = now // w + 1
            x = now % w + 1
            if seen[y][x] is False:
                if maps[y][x] == 0:
                    seen[y][x] = True
                else:
                    ans += 1
                    dfs(y, x)
            
            now += 1
        
        print(ans)

Python: import sys
sys.setrecursionlimit(10**8)

ans = []

def dfs(x, y):
    c[x][y] = 0

    for dx in range(-1, 2):
        for dy in range(-1, 2):
            nx = x + dx
            ny = y + dy

            if 0 <= nx < h and 0 <= ny < w and c[nx][ny] == 1:
                dfs(nx, ny)

while True:
    w, h = map(int, input().split())
    if w == 0 and h ==0:
        break

    count = 0

    c = [[] for _ in range(h)]
    for i in range(h):
        if w == 1:
            c[i] = [int(input())]
        else:
            c[i] = list(map(int, input().split()))

    for x in range(h):
        for y in range(w):
            if c[x][y] == 1:
                dfs(x, y)
                count += 1

    ans.append(count)

for i in ans:
    print(i)

Python: import sys
sys.setrecursionlimit(5000)

dx = [1, 0, -1]
dy = [1, 0, -1]

def dfs(area, x, y):
    area[x][y] = 0
    for i in dx:
        for j in dy:
            next_x = x + i
            next_y = y + j
            if area[next_x][next_y] == 1:
                dfs(area, next_x, next_y)

def solver(w, h):
    ans = 0
    area = [[0]*(w+2)]
    for i in range(h):
        area.append([0]+list(map(int, input().split()))+[0])
    area.append([0]*(w+2))

    for i in range(1, h+1):
        for j in range(1, w+1):
            if area[i][j] == 1:
                ans += 1
                dfs(area, i, j)
    return ans

while True:
    w, h = map(int, input().split())
    if w == h == 0:
        break
    print(solver(w, h))