Go: // AOJ 1160: How Many Islands? http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=1160

package main

import (
	"bufio"
	"container/list"
	"fmt"
	"os"
	"strconv"
)

var SEA = 0
var LAND = 1

func nextInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

func discoverIslands(M, V [][]int, H, W int) int {
	// 島を探す
	queue := list.New()
	islands := 0
	for i := 1; i <= H; i++ {
		for j := 1; j <= W; j++ {
			// 訪問済みの土地ならスキップ
			if V[i][j] == 1 {
				continue
			}

			// 訪問中の土地が海なら訪問済みにしてスキップ
			if M[i][j] == SEA {
				V[i][j] = 1
				continue
			}

			// 未訪問の陸地が見つかったので
			// 島の数を1つ増やし、この陸地から辿れる陸地を訪問していく
			islands++
			queue.PushBack([]int{i, j})

			for queue.Len() > 0 {
				cur := queue.Remove(queue.Front()).([]int)
				h, w := cur[0], cur[1]
				if V[h][w] == 1 {
					continue
				}
				V[h][w] = 1

				// 全方向に未訪問の陸地がないか探索
				for v := -1; v <= 1; v++ {
					for l := -1; l <= 1; l++ {
						dh := h + v
						dw := w + l
						if M[dh][dw] == LAND && V[dh][dw] == 0 {
							queue.PushBack([]int{dh, dw})
						}
					}
				}
				/*
					if M[h-1][w] == LAND {
						queue.PushBack([]int{h - 1, w})
					}
					if M[h-1][w+1] == LAND {
						queue.PushBack([]int{h - 1, w + 1})
					}
					if M[h][w+1] == LAND {
						queue.PushBack([]int{h, w + 1})
					}
					if M[h+1][w+1] == LAND {
						queue.PushBack([]int{h + 1, w + 1})
					}
					if M[h+1][w] == LAND {
						queue.PushBack([]int{h + 1, w})
					}
					if M[h+1][w-1] == LAND {
						queue.PushBack([]int{h + 1, w - 1})
					}
					if M[h][w-1] == LAND {
						queue.PushBack([]int{h, w - 1})
					}
					if M[h-1][w-1] == LAND {
						queue.PushBack([]int{h - 1, w - 1})
					}
				*/
			}
		}
	}
	return islands
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	for {
		W, H := nextInt(sc), nextInt(sc)

		if W == 0 && H == 0 {
			break
		}
		// Initialize map and visted list
		M := make([][]int, H+2)
		V := make([][]int, H+2)
		for i := 0; i < H+2; i++ {
			M[i] = make([]int, W+2)
			V[i] = make([]int, W+2)
		}
		for i := 1; i <= H; i++ {
			for j := 1; j <= W; j++ {
				M[i][j] = nextInt(sc)
			}
		}

		islands := discoverIslands(M, V, H, W)

		fmt.Println(islands)
	}
}

Python: from collections import deque
import sys
sys.setrecursionlimit(10000)

seen=[]
first_order =[]
last_order = []

def dfs(g, v, first_ptr, last_ptr):
    first_ptr=first_ptr+1
#    last_ptr=first_ptr
    
    first_order[v] = first_ptr
    seen[v]=True 
    for next_v in g[v]:
        if seen[next_v]:
            continue
        first_ptr, last_ptr=dfs(g, next_v, first_ptr, last_ptr)
    last_ptr=last_ptr+1
 #   first_ptr=last_ptr

    last_order[v] = last_ptr
    return first_ptr, last_ptr


while True:
    w,h=map(int,input().split())
    if w==0 and h==0:
        break
    c=[[0]*w for i in range(h)]
    for i in range(h):
        c[i]=list(map(int,input().split()))
    
    n=w*h
    g = [deque([]) for _ in range(n + 1)]
    for jh in range(h):
        for jw in range(w):
            if c[jh][jw]==0:
                continue
            i=w*jh+jw
#            print(jh,jw,i,c[jh][jw])
            if jh<h-1 :
                kh=jh+1
                kw=jw
                if c[kh][kw]==1:
                    ii=w*(kh)+kw
                    g[i].append(ii)
#                    g[ii].append(i)
            if jh>0 :
                kh=jh-1
                kw=jw
                if c[kh][kw]==1:
                    ii=w*(kh)+kw
                    g[i].append(ii)
#                    g[ii].append(i)
            if jw<w-1 :
                kh=jh
                kw=jw+1
                if c[kh][kw]==1:
                    ii=w*(kh)+kw
                    g[i].append(ii)
#                    g[ii].append(i)
            if jw>0 :
                kh=jh
                kw=jw-1
                if c[kh][kw]==1:
                    ii=w*(kh)+kw
                    g[i].append(ii)
#                    g[ii].append(i)
            if jw<w-1 and jh<h-1:
                kh=jh+1
                kw=jw+1
                if c[kh][kw]==1:
                    ii=w*(kh)+kw
                    g[i].append(ii)
#                    g[ii].append(i)
            if jw>0 and jh>0:
                kh=jh-1
                kw=jw-1
                if c[kh][kw]==1:
                    ii=w*(kh)+kw
                    g[i].append(ii)
#                    g[ii].append(i)
            if jw<w-1 and jh>0:
                kh=jh-1
                kw=jw+1
                if c[kh][kw]==1:
                    ii=w*(kh)+kw
                    g[i].append(ii)
#                    g[ii].append(i)
            if jw>0 and jh<h-1:
                kh=jh+1
                kw=jw-1
                if c[kh][kw]==1:
                    ii=w*(kh)+kw
                    g[i].append(ii)
 #                   g[ii].append(i)

    seen=[False]*n
    first_ptr=0
    last_ptr=0
    first_order =[-1]*n
    last_order = [-1]*n

    icnt=0
    for jh in range(h):
        for jw in range(w):
            v=w*jh+jw
            if c[jh][jw]==1:
                if seen[v]:
                    continue
                else:
                    first_ptr, last_ptr=dfs(g,v,first_ptr, last_ptr)
                    icnt+=1

    print(icnt)

Python: #!/usr/bin/env python
# -*- coding: utf-8 -*-

def dfs(s,Map,H,W,c):
    dxdy = [(1,0),(-1,0),(0,1),(0,-1),(1,1),(-1,-1),(-1,1),(1,-1)]
    for i in range(3):
        Map[s[0]][s[1]] = c
        nextPos = (s[0]+dxdy[i][0],s[1]+dxdy[i][1])
        if nextPos[0] >= 0 and nextPos[1] >= 0 and nextPos[0] < H and nextPos[1] < W:
            if Map[nextPos[0]][nextPos[1]] == 1:
                dfs(nextPos,Map,H,W,c)

while True:
    W,H = map(int,input().split(" "))
    if W == 0 and H == 0:
        break
    Map = [list(map(int,input().split())) for i in range(0,H)]
    c = 1
    for i in range(H):
        for j in range(W):
            if Map[i][j] == 1:
                c += 1
                dfs((i,j),Map,H,W,c)
    print(c-1)

Python: from collections import deque
ss = [0,1,0,-1]
dd = [1,0,-1,0]
while True:
    w,h = map(int ,input().split())
    if w == h == 0:
        break
    ll = []
    for i in range(h):
        ll.append(list(map(int, input().split())))
    cnt = 0
    passed = [[False]*w for i in range(h)]
    q = deque()
    for i in range(h):
        for j in range(w):
            if passed[i][j]:
                continue
            if ll[i][j] == 1:
                passed[i][j] = True
                q.append([i,j])
                cnt += 1
                while q:
                    l = q.popleft()
                    a,b = l[0], l[1]
                    for s in ss:
                        for d in dd:
                            if s == d == 0:
                                continue
                            ta = a + s
                            tb = b + d
                            if 0 <= ta <= h-1 and 0 <= tb <= w-1 and ll[ta][tb] == 1 and not passed[ta][tb]:
                                passed[ta][tb] = True
                                q.append([ta,tb])
    print(cnt)

Python: import sys
input = sys.stdin.readline
sys.setrecursionlimit(1000000000)

def main():
    while True:
        W, H = map(int, input().split())
        if W == 0:
            break
        board = [list(map(int, input().split())) for i in range(H)]
        check = [[False] * W for i in range(H)]

        def dfs(x, y):
            check[y][x] = True
            for nx, ny in [(x, y-1), (x+1, y-1), (x+1, y), (x+1, y+1), (x, y+1), (x-1, y+1), (x-1, y), (x-1, y-1)]:
                if 0 <= nx and nx < W and 0 <= ny and ny < H:
                    if not check[ny][nx] and board[ny][nx] == 1:
                        dfs(nx, ny)

        ans = 0
        for y in range(H):
            for x in range(W):
                if not check[y][x] and board[y][x] == 1:
                    ans += 1
                    dfs(x, y)
        print(ans)


if __name__ == "__main__":
    main()