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: # Union Find
#0オリジン以下注意

#xの根を求める
def find(x):
    if par[x] < 0:
        return x
    else:
        par[x] = find(par[x])
        return par[x]
    
def unite(x, y):
    x = find(x)
    y = find(y)
    
    if x == y:
        return False
    else:
        #sizeの大きい方がx
        if par[x] > par[y]:
            x, y = y, x
        par[x] += par[y] #ここで集合の個数を更新している
        par[y] = x
        return True
    
#xとyが同じ集合に含まれているかどうかを判定(同じ集合にあればTrue)
def same(x, y):
    return find(x) == find(y)

#xが属する集合の個数
def size(x):
    return -par[find(x)]

#初期化
#根なら-size, 子なら親の頂点
################以下にコードを書く

while True:
    w, h = map(int, input().split())
    par = [-1]*(w*h)
    if (w, h) == (0, 0):
        break
    li = []
    for i in range(h):
        li.append(list(map(int, input().split())))
    for i in range(h):
        for j in range(w-1):
            if li[i][j] == li[i][j+1]:
                unite(w*i+j, w*i+j+1)
    for j in range(w):
        for i in range(h-1):
            if li[i][j] == li[i+1][j]:
                unite(w*i+j, w*i+j+w)
    for i in range(h):
        for j in range(w):
            I1 = i+1
            I2 = i-1
            J = j+1
            if 0 <= I1 and I1<h and 0<=J and J<w:
                if li[i][j] == 1 and li[I1][J] == 1:
                    unite(w*i+j, w*I1+J)
            if 0 <= I2 and I2<h and 0<=J and J<w:
                if li[i][j] == 1 and li[I2][J] == 1:
                    unite(w*i+j, w*I2+J)

                    
    #島を数える
    #陸のリスと
    li_riku = []
    for i in range(h):
        for j in range(w):
            if li[i][j]==1:
                li_riku.append(w*i+j)
    li_island = []
    sum_size = len(li_riku)
    for i in li_riku:
        k = find(i)
        if k not in li_island:
            li_island.append(k)
    print(len(li_island))

Python: import sys
sys.setrecursionlimit(10000)
def f(x,y):
    a[y][x]='0'
    for dx,dy in[[-1,0],[1,0],[0,-1],[0,1],[-1,-1],[1,-1],[-1,1],[1,1]]:
        dx+=x;dy+=y
        if 0<=dx<w and 0<=dy<h and a[dy][dx]=='1':f(dx,dy)
while 1:
    w,h=map(int,input().split())
    if w==0:break
    a=[list(input().split()) for _ in[0]*h];b=0
    for i in range(w):
        for j in range(h):
            if a[j][i]=='1':
                b+=1;f(i,j)
    print(b)

Python: import sys
sys.setrecursionlimit(10 ** 9)

first = True
while True:
    W, H = map(int, sys.stdin.readline().strip().split())
    if (W == 0) and (H == 0):
        break

    fp = [True] * (W * H)  # 探索可能示す

    M = []
    for h in range(H):
        m = list(map(int, sys.stdin.readline().strip().split()))
        M.append(m)
        for i, j in enumerate(m):
            if j == 0:
                fp[h * W + i] = False


    def dfs(u):  # u は座標
        x, y = u
        fp[y * W + x] = False  # 探索済みを示す

        for i in [-1, 0, 1]:
            x_next = x + i
            if (x_next < 0) or (x_next > W - 1):
                continue
            for j in [-1, 0, 1]:
                y_next = y + j
                if (y_next < 0) or (y_next > H - 1):
                    continue
                # print(f'y_next: {y_next}, x_next: {x_next}')
                # print(f'{fp[y_next * W + x_next]}')
                # print(f'{M[y][x]}')
                if fp[y_next * W + x_next] and (M[y][x] == 1):
                    dfs((x_next, y_next))


    count = 0
    while True in fp:
        count += 1
        # print(f'count : {count}')
        # print(f'fp: {fp}')

        y = int((fp.index(True) / W))
        x = int((fp.index(True) - y * W))
        # print(f'x: {x}, y: {y}')
        dfs((x, y))

    # if first:
    #     first = False
    # else:
    #     print('\n', end='')
    print(count, end='\n')

Python: # -*- coding: utf-8 -*-
#150 島は幾つある？
h,w=1,1

count=0
anser=0

def search(x,y):
    #マップの外側か壁の場合は何もしない
    #print(x,y)

    global count
    count+=1
    if x<0 or x>w-1 or y<0 or y>h-1 or map_data[y][x]==0:
 
        return
        
    
    #以前に到達していたら何もしない
    if reached[y][x] ==0:
         return

    reached[y][x]=0
    
    #print("aa")



    search(x+1,y)#右
    search(x-1,y)#左
    search(x,y+1)#上
    search(x,y-1)#下
    search(x-1,y-1)
    search(x-1,y+1)
    search(x+1,y-1)
    search(x+1,y+1)



while h!=0 and w!=0: 
    anser=0
    count=1
    #グラフの入力方法------

    w,h=map(int ,raw_input().split())
    if h==0 and w==0:
        break

    map_data = [[0]*w for _ in range(h)]
    reached = [[1]*w for _ in range(h)]

    for i in range(h):
        ct = raw_input().split()
       
        for j in range(w):
            map_data[i][j] = int(ct[j])
            reached [i][j]=int(ct[j])
            if ct[j]==1:
                sx=j
                sy=i

    t=0
    a=0
    while a<=h:
       if 1 in reached[t%h]:         
            search(reached[t%h].index(1),t%h)
            anser+=1
            #print("count",count)
            count=1
            a=0
       elif count==h:
                break
       t+=1
       a+=1

    print(anser)

Python: import sys
input=sys.stdin.readline
sys.setrecursionlimit(10 ** 6)
#from collections import defaultdict
#d = defaultdict(int)
#import fractions
#import math
#import collections
#from collections import deque
#from bisect import bisect_left
#from bisect import insort_left
#N = int(input())
#A = list(map(int,input().split()))
#S = list(input())
#S.remove("\n")
#N,M = map(int,input().split())
#S,T = map(str,input().split())
#A = [int(input()) for _ in range(N)]
#S = [input() for _ in range(N)]
#A = [list(map(int,input().split())) for _ in range(N)]
#import itertools
#import heapq
#import numpy as np
def dfs(curx,cury):
    global Map
    if Map[cury][curx] == 1:
        Map[cury][curx] = 0
        dfs(curx+1,cury)
        dfs(curx-1,cury)
        dfs(curx,cury+1)
        dfs(curx,cury-1)
        dfs(curx+1,cury-1)
        dfs(curx-1,cury-1)
        dfs(curx-1,cury+1)
        dfs(curx+1,cury+1)
    else:
        return
w = -1
h = -1
while(w != 0 and h != 0):
    w,h = map(int,input().split())
    if w == 0 and h == 0:
        break
    Map = [[0]*(w+2)]
    for _ in range(h):
        li = list(map(int,input().split()))
        a = [0]+li+[0]
        Map.append(a)
    Map.append([0]*(w+2))
    s = 0
    for i in range(w):
        for j in range(h):
            if Map[j+1][i+1] == 1:
                s += 1
                dfs(i+1,j+1)
    print(s)

Python: import sys
sys.setrecursionlimit(10**6)

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 1:
    w,h = map(int,input().split())
    c = [input().split() for _ in range(h)]
    
    if w == 0 and h == 0:
        break
    cnt = 0
    for i in range(h):
        for j in range(w):
            if c[i][j] == "1":
                dfs(i,j)
                cnt += 1

    print(cnt)