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: # http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=1160&lang=jp

import sys
sys.setrecursionlimit(10000)


def dfs(x: int, y: int):
    """dfsで1つの地続きの島を探索
    Parameters
    ----------
        x, y : 探索対称点のxy座標
    """
    seen[x][y] = True
    for i in range(8):
        nx = x + dx[i]
        ny = y + dy[i]
        if (0 <= nx < H
                and 0 <= ny < W
                and seen[nx][ny] is False
                and chart[nx][ny] == 1):
            dfs(nx, ny)


while True:
    try:
        W, H = map(int, input().split())
        if W == 0:
            break
        else:
            chart = []
            for _ in range(H):
                chart.append(list(map(int, input().split())))
            seen = [[False] * W for _ in range(H)]
            dx = [1, 0, -1, 0, 1, 1, -1, -1]
            dy = [0, 1, 0, -1, 1, -1, -1, 1]
            ans = 0
            for i in range(H):
                for j in range(W):
                    # seen=Trueのマスは既に島としてカウントされた故それ以外を探索
                    if seen[i][j] is False and chart[i][j] == 1:
                        dfs(i, j)
                        # dfsで島1つを探索終了した故カウントをインクリメント
                        ans += 1
            print(ans)
    except ValueError:
        break

Python: def erase(x, y):
    c[y][x] = '0'
    for dx, dy in ((1, 0), (1, 1), (0, 1), (-1, 1), (-1, 0), (-1, -1), (0, -1), (1, -1)):
        nx, ny = x + dx, y + dy
        if 0 <= nx <= w -1 and 0 <= ny <= h - 1:
            if c[ny][nx] == '1':
                erase(nx, ny)

while True:
    w, h = map(int, input().split())
    if w == h == 0:
        break
    c = [[i for i in input().split()] for _ in range(h)]
    ans = 0
    for y in range(h):
        for x in range(w):
            if c[y][x] == '1':
                ans += 1
                erase(x, y)
    print(ans)

Python: # -*- coding: utf-8 -*-
import sys
sys.setrecursionlimit(10000)


def search(n, m, tile, N, M):
    for dy, dx in zip([-1, -1, -1, 0, 0, 1, 1, 1], [-1, 0, 1, -1, 1, -1, 0, 1]):
        if 0 <= dy + n < N and 0 <= dx + m < M:
            if tile[dy + n][dx + m] == '1':
                tile[dy + n][dx + m] = '2'
                search(dy + n, dx + m, tile, N, M)


while True:
    M, N = map(int, input().split())
    if M == 0 and N == 0:
        break
    tile = [input().split() for n in range(N)]
    ans = 0
    for n in range(N):
        for m in range(M):
            if tile[n][m] == '1':
                tile[n][m] = '2'
                search(n, m, tile, N, M)
                ans += 1
    print(ans)

Python: import copy

move = ((1, 0), (0, 1), (0, -1), (-1, 0), (1, 1), (-1, -1), (-1, 1), (1, -1))


def dfs(start):
    field[start[1]][start[0]] = '0'
    CP = [start]
    while CP:
        NP = []
        for cp in CP:
            for m in move:
                n_p = (cp[0]+m[0], cp[1]+m[1])
                if not(n_p[0] < 0 or n_p[1] < 0 or n_p[1] >= h or n_p[0] >= w) and field[n_p[1]][n_p[0]] == '1':
                    field[n_p[1]][n_p[0]] = '0'
                    NP.append(n_p)
        CP = NP


while True:
    w, h = map(int, input().split())
    if w == 0 and h == 0:
        break
    field = [list(input().split()) for _ in range(h)]
    count = 0
    for y in range(h):
        for x in range(w):
            if field[y][x] == '1':
                dfs((x, y))
                count += 1
    print(count)

Python: #00:45
import sys

sys.setrecursionlimit(10000000)


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



#左上からせめて深さ優先で探索する問題
while True:
    # 地図作る
    count = 0
    width,hight = map(int,input().split())
    if width ==0 :
        break
    d =[]
    for _ in range(hight):
        d.append(list(map(int,input().split())))
    
    def dfs(x, y):
    # いまたどり着いたはずなので1に塗りつぶす
        d[y][x]=0

    #4方向ループ
    #あくまで方向の表し方dxは
        for i in range(8):
            ny = y + dx[i]
            nx = x + dy[i]

        #行ったことがなくって、迷路の範囲内で、障害物がなければ、進む
            if 0 <= ny and ny < hight \
              and 0 <= nx and nx < width \
              and d[ny][nx] == 1:
                dfs(nx,ny) 

    

    for y in range(hight):
        for x in range(width):            
            if d[y][x] == 1:
                count = count + 1
                dfs(x,y)
    print(count)

Python: def erase(w, h, x, y):
    c[y][x] = '0'
    for dx, dy in ((1, 0), (1, 1), (0, 1), (-1, 1), (-1, 0), (-1, -1), (0, -1), (1, -1)):
        nx, ny = x + dx, y + dy
        if 0 <= nx <= w -1 and 0 <= ny <= h - 1:
            if c[ny][nx] == '1':
                erase(w, h, nx, ny)

while True:
    w, h = map(int, input().split())
    if w == h == 0:
        break
    c = [[i for i in input().split()] for _ in range(h)]
    ans = 0
    for y in range(h):
        for x in range(w):
            if c[y][x] == '1':
                ans += 1
                erase(w, h, x, y)
    print(ans)

Python: # -*- coding: utf-8 -*-

w, h = map(int,input().split())
c = [list(map(int,input().split())) for j in range(h)]
count = 0

def dfs(x,y):
    c[x][y] = 0
    for dx in [-1,0,1]:
        for dy in [-1,0,1]:
            nx = x + dx
            ny = y + dy
            if(0 <= nx < w and 0 <= ny <= h and c[nx][ny] == 1 ):
                dfs(nx, ny)
    
for i in range(h):
    for j in range(w):
        if (c[i][j] == 1):
            dfs(i,j)
            count += 1

print(count)