Go: package main

import (
	"bufio"
	"fmt"
	"io"
	"math"
	"os"
	"strconv"
)

var (
	readString func() string
	readBytes  func() []byte
	stdout     *bufio.Writer
)

func init() {
	readString, readBytes = newReadString(os.Stdin)
	stdout = bufio.NewWriter(os.Stdout)
}

func newReadString(ior io.Reader) (func() string, func() []byte) {
	r := bufio.NewScanner(ior)
	r.Buffer(make([]byte, 1024), math.MaxInt32)
	r.Split(bufio.ScanWords)

	f1 := func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
	f2 := func() []byte {
		return []byte(f1())
	}
	return f1, f2
}

func readInt() int {
	return int(readInt64())
}

func readInt64() int64 {
	i, err := strconv.ParseInt(readString(), 10, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

func readFloat64() float64 {
	f, err := strconv.ParseFloat(readString(), 64)
	if err != nil {
		panic(err.Error())
	}
	return f
}

func printf(f string, args ...interface{}) (int, error) {
	return fmt.Fprintf(stdout, f, args...)
}

func println(args ...interface{}) (int, error) {
	return fmt.Fprintln(stdout, args...)
}

func eprintln(args ...interface{}) (int, error) {
	return fmt.Fprintln(os.Stderr, args...)
}

func eprintf(f string, args ...interface{}) (int, error) {
	return fmt.Fprintf(os.Stderr, f, args...)
}

func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}

func min64(a, b int64) int64 {
	if a < b {
		return a
	}
	return b
}

func max(a, b int) int {
	if a < b {
		return b
	}
	return a
}

func max64(a, b int64) int64 {
	if a < b {
		return b
	}
	return a
}

func abs(a int) int {
	if a < 0 {
		return -a
	}
	return a
}

func abs64(a int64) int64 {
	if a < 0 {
		return -a
	}
	return a
}

func gcd(a, b int) int {
	if b == 0 {
		return a
	}
	return gcd(b, a%b)
}

func gcd64(a, b int64) int64 {
	if b == 0 {
		return a
	}
	return gcd64(b, a%b)
}

// readString() string
// readInt() int
// readInt64() int64
// readFloat64() float64

// -----------------------------------------------------------------------------

func main() {
	defer stdout.Flush()

	for {
		ans, ok := solve()
		if !ok {
			break
		}
		println(ans)
	}

}

func solve() (int, bool) {
	w := readInt()
	h := readInt()
	if w == 0 && h == 0 {
		return 0, false
	}

	c := make([][]int, h+2)
	c[0] = make([]int, w+2)
	c[h+1] = make([]int, w+2)
	for i := 1; i-1 < h; i++ {
		c[i] = make([]int, w+2)
		for j := 1; j-1 < w; j++ {
			c[i][j] = readInt()
		}
	}

	var ans int
	for i := 1; i-1 < h; i++ {
		for j := 1; j-1 < w; j++ {
			if 0 < c[i][j] {
				ans++
				dfs(c, i, j)
			}
		}
	}
	return ans, true
}

func dfs(c [][]int, y, x int) {
	c[y][x] = 0
	dx := []int{-1, 0, 1, -1, 1, -1, 0, 1}
	dy := []int{-1, -1, -1, 0, 0, 1, 1, 1}
	for i := range dx {
		nx := x + dx[i]
		ny := y + dy[i]
		if 0 < c[ny][nx] {
			dfs(c, ny, nx)
		}
	}
}

// -----------------------------------------------------------------------------

Python: # import numpy
import sys

sys.setrecursionlimit(10**6)

digtmp = [[0, 1], [1, 1], [1, 0], [1, -1], [0, -1], [-1, -1], [-1, 0], [-1, 1]]

def dfs(i, j):
    global dfsflag
    if Mapdata[i][j] == 1 and Mapcheck[i][j] == 0:
        Mapcheck[i][j] = 1
        dfsflag = 1
        for tmp in digtmp:
            digh = i + tmp[0]
            digw = j + tmp[1]
            if 0 <= digh < h and 0 <= digw < w:
                dfs(digh, digw)
    else:
        Mapcheck[i][j] = 1

while True:
    w, h = map(int, input().split())
    if w == 0 and h == 0:
        break
    Mapdata = []
    for _ in range(h):
        tmp = list(map(int, input().split()))
        Mapdata.append(tmp)
    Mapcheck = [[0] * w for _ in range(h)]
    count = 0
    for i in range(h):
        for j in range(w):
            dfsflag = 0
            dfs(i, j)
            if dfsflag == 1:
                count += 1
    print(count)

Python: from itertools import product
import sys

sys.setrecursionlimit(1000000)

def s(m, x, y):
    m[y][x] = 0

    for dx, dy in product(range(-1, 2), range(-1, 2)):
        if m[y + dy][x + dx]:
            s(m, x + dx, y + dy)

while True:
    c = 0
    w, h = map(int, input().split())

    if w == h == 0:
        break

    m = [[0] * (w + 2)] + [[0] + list(map(int, input().split())) + [0] for _ in range(h)] + [[0] * (w + 2)]

    for x, y in product(range(w + 2), range(h + 2)):
        if m[y][x]:
            c += 1
            s(m, x, y)
            
    print(c)

Python: import sys
sys.setrecursionlimit(10 ** 5)
 
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 and 0 <= ny < h and c[ny][nx] == '1':
            erase(nx, ny)
 
while True:
    w, h = map(int, input().split())
    if w == h == 0:
        break
    c = [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: import math,string,itertools,fractions,heapq,collections,re,array,bisect,sys,random,time

sys.setrecursionlimit(10**7)
inf = 10**20
mod = 10**9 + 7

stdin = sys.stdin

ni = lambda: int(ns())
na = lambda: list(map(int, stdin.readline().split()))
ns = lambda: stdin.readline().rstrip()  # ignore trailing spaces

a = [(x, y) for x in range(-1, 2) for y in range(-1, 2) if not (x == 0 and y == 0)]
def dfs(g, i, j):
    g[i][j] = 0
    for dx, dy in a:
        nx = i + dx
        ny = j + dy
        if 0 <= nx < h and 0 <= ny < w and g[nx][ny] == 1:
            dfs(g, nx, ny)

while True:
    w, h = na()
    if w == 0 and h == 0:
        break
    g = [na() for _ in range(h)]
    #seen = [[False] * w for _ in range(h)]
    ans = 0
    for i in range(h):
        for j in range(w):
            if g[i][j] == 1:
                dfs(g, i, j)
                ans += 1
    print(ans)

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(10000)
def f(x,y):
    if 0<=x<w and 0<=y<h and a[y][x]=='1':
        a[y][x]='0'
        for dx,dy in[[-1,0],[1,0],[0,-1],[0,1],[-1,-1],[1,-1],[-1,1],[1,1]]:f(x+dx,y+dy)
while 1:
    w,h=map(int,input().split())
    if w==0:break
    a=[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)