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 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)

Python: def root(i):
    global roots
    if roots[i]==i:
        return i
    else:
        roots[i]=root(roots[i])
        return roots[i]

def unite(i, j):
    global roots
    ri=root(i)
    rj=root(j)
    #roots[max(ri, rj)]=min(ri, rj)
    if ri==rj: return
    roots[ri]=rj

directions=[(-1, 0), (1, 0), (0, -1), (0, 1), (-1, -1), (-1, 1), (1, -1), (1, 1)]
while True:
    l=input().split()
    w=int(l[0])
    h=int(l[1])
    if w==0 and h==0: break
    map=[[False for _ in range(h+2)] for _ in range(w+2)]
    roots=[i for i in range((w+2)*(h+2))]
    for hi in range(h):
        l=input().split()
        for wi in range(w):
            map[wi+1][hi+1]=bool(int(l[wi]))

    for hi in range(1, h+1):
        for wi in range(1, w+1):
            if not map[wi][hi]: continue
            i=hi*(w+2)+wi
            for d in directions:
                if not map[wi+d[0]][hi+d[1]]: continue
                j=(hi+d[1])*(w+2)+(wi+d[0])
                unite(i, j)
    res=set()
    for hi in range(1, h+1):
        for wi in range(1, w+1):
            if not map[wi][hi]: continue
            i=hi*(w+2)+wi
            res.add(root(i))
    print(len(res))