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 itertools import product as pro
sys.setrecursionlimit(10**7)

while True:
    w,h=map(int,input().split())
    if w==0 and h==0:
        sys.exit()
    
    G=[]
    for i in range(h):
        G.append(list(map(int,input().split())))

    #隣接する島
    def sur(X):
        x=X[0]
        y=X[1]
        axis_x=[x+1,x,x-1]
        axis_y=[y+1,y,y-1]
        preE=list(pro(axis_x,axis_y))
        preE.remove((x,y))
        E=[]
        for e in preE:
            if 0<=e[0]<=h-1 and 0<=e[1]<=w-1:
                if G[e[0]][e[1]]==1:
                    E.append(e)
        return E

    check=[[False]*w for i in range(h)]

    #checkの陸埋めをしても良い
    def dfs(v):
        check[v[0]][v[1]]=True
        for next in sur(v):
            if check[next[0]][next[1]]:
                continue
            dfs(next)

    ans=0
    for i in range(h):
        for j in range(w):
            if not check[i][j] and G[i][j]==1:
                ans+=1
                dfs((i,j))
    
    print(ans)

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

w=0;h=0;
def dfs(x,y,Map):
    #ending condition
    if not (0 <= x and x < h and 0 <= y and y < w):
        return
    if Map[x][y] == 0:
        return
    
    #operation
    Map[x][y] = 0

    #moving deep
    for i in [-1,0,1]:
        for j in [-1,0,1]:
            dfs(x+i,y+j,Map)

def start_cnt():
    global w,h
    w,h = map(int,input().split())
    if w == 0 and h == 0:exit();
    cnt = 0
    Map = []
    for i in range(h):
            Map.append(list(map(int,input().split())))
    for i in range(h):
        for j in range(w):
            if Map[i][j] == 1:
                dfs(i,j,Map)
                cnt += 1
    print(cnt)
while True:
    start_cnt()

Python: import sys
input = lambda: sys.stdin.readline().rstrip()
sys.setrecursionlimit(10**6)
def dfs(a,v):
    global st,per
    if v in st: st.remove(v)
    else: return
    for tom in per:
        if a[v[0]+tom[0]][v[1]+tom[1]]==1: dfs(a,(v[0]+tom[0],v[1]+tom[1]))
while True:
    c,r=map(int,input().split())
    if c==0 and r==0 : exit(0)
    a=[[0]*(c+2)]
    for j in range(r):
        a.append([0]+[int(i) for i in input().split()]+[0])
    a.append([0]*(c+2))
    st=set()
    for i in range(len(a)):
        for j in range(len(a[i])):
            if a[i][j]==1:
                st.add((i,j))
    per=[[1,1],[1,0],[0,1],[-1,1],[1,-1],[-1,-1],[-1,0],[0,-1]]
    ans=0
    while st:
        ans+=1
        for i in st:
            dfs(a,i)
            break
    print(ans)

Python: import sys
sys.setrecursionlimit(10**7)

def dfs(row, column):
    Map[row][column] = num
    for i in range(-1, 2):
        for j in range(-1, 2):
            if Map[row + i][column + j] == 1:
                dfs(row + i, column + j)

while True:
    w, h = map(int, input().split())
    if w == h == 0:
        break
    
    Map = [[0] * (w+2)]
    Map += [[0] + list(map(int, input().split())) + [0] for _ in range(h)]
    Map += [[0] * (w+2)]
    
    num = 1
    
    for i in range(h+2):
        for j in range(w+2):
            if Map[i][j] == 1:
                num += 1
                dfs(i,j)
    print(num-1)

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(len(dxdy)):
        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: import sys
sys.setrecursionlimit(10 ** 7)

direction = ((1, 0), (-1, 0), (0, 1), (0, -1), (1, 1), (-1, -1), (-1, 1), (1, -1))


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

    for d in direction:
        nh = y + d[1]
        nw = x + d[0]

        if nh < 0 or nh >= h or nw < 0 or nw >= w:
            continue
        if board[nh][nw] == 0:
            continue
        dfs(nh, nw)

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

    cnt = 0
    for y in range(h):
        for x in range(w):
            if board[y][x] == 0:
                continue
            dfs(y, x)
            cnt += 1
    print(cnt)

Python: def dfs(c, x, y, w, h):
    c[y][x] = -1

    for i in range(-1, 2):
        for j in range(-1, 2):
            if i == 0 and j == 0:
                continue
            x_ = x + i
            y_ = y + j
            if 0 <= x_ < w and 0 <= y_ < h and c[y_][x_] == 1:
                dfs(c, x_, y_, w, h)

def solve(w, h):
    c = []
    ans = 0

    for _ in range(h):
        c.append(list(map(int, input().split())))

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

    print(ans)

if __name__ == "__main__":
    import sys
    sys.setrecursionlimit(10000)
    while True:
        w, h = map(int, input().split())
        if w * h == 0:
            break
        solve(w, h)

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

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)