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)
		}
	}
}

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

C++: #include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define repi(i, a, b) for (int i = int(a); i < int(b); ++i)
typedef long long ll;
long long mod = 1e9 + 7;
const long long INF = 1LL << 60;
using namespace std;

template <class T>
inline bool chmin(T &a, T b)
{
    if (a > b)
    {
        a = b;
        return true;
    }
    return false;
}

template <class T>
inline bool chmax(T &a, T b)
{
    if (a < b)
    {
        a = b;
        return true;
    }
    return false;
}

int wi, he;
int c[100][100];
bool seen[100][100];

void dfs(int w, int h)
{
    if (c[w][h] == 1 && seen[w][h] == false)
    {
        seen[w][h] = true;
        if (c[w + 1][h] == 1)
        {
            dfs(w + 1, h);
        }

        if (c[w - 1][h] == 1)
        {
            dfs(w - 1, h);
        }

        if (c[w][h - 1] == 1)
        {
            dfs(w, h - 1);
        }

        if (c[w][h + 1] == 1)
        {
            dfs(w, h + 1);
        }

        if (c[w + 1][h + 1] == 1)
        {
            dfs(w + 1, h + 1);
        }

        if (c[w + 1][h - 1] == 1)
            dfs(w + 1, h - 1);

        if (c[w - 1][h + 1] == 1)
            dfs(w - 1, h + 1);

        if (c[w - 1][h - 1] == 1)
            dfs(w - 1, h - 1);
    };
}

int main()
{
    vector<int> res;
    while (true)
    {
        int ans = 0;

        rep(i, 100) rep(j, 100)
        {
            c[i][j] = 0;
            seen[i][j] = 0;
        }

        cin >> wi >> he;
        if (wi == 0 && he == 0)
            break;

        repi(j, 1, he + 1) repi(i, 1, wi + 1)
        {
            cin >> c[i][j];
        };

        repi(i, 1, wi + 1) repi(j, 1, he + 1)
        {
            if (c[i][j] == 1 && seen[i][j] == false)
            {
                dfs(i, j);
                ans++;
            }
        }

        res.push_back(ans);
    }

    for (auto r : res)
    {
        cout << r << endl;
    }
    return 0;
}

C++: #include <bits/stdc++.h>
#define debug(x) cerr << #x << ": " << x << '\n';
using namespace std;
using ll = long long;
using P = pair<int, int>;
const int INF = (int)1e9;

int w, h;
int c[51][51];
int dx[] = {1, -1, 0, 0, 1, 1, -1, -1};
int dy[] = {0, 0, 1, -1, 1, -1, 1, -1};

void dfs(int y, int x){
	c[y][x] = 0;
	for(int i = 0; i < 8; i++){
		int ny = y + dy[i], nx = x + dx[i];
		if(0<=ny and ny<h and 0<=nx and nx<w and c[ny][nx]==1){
			dfs(ny, nx);
		}
	}
}

int solve(){
	int res = 0;
	for(int i = 0; i < h; i++){
		for(int j = 0; j < w; j++){
			if(c[i][j] == 1){
				dfs(i, j);
				res++;
			}
		}
	}

	return res;
}

int main(void){
	while(scanf("%d%d", &w, &h) != EOF){
		if(w == 0 and h == 0) break;
		for(int i = 0; i < h; i++){
			for(int j = 0; j < w; j++){
				scanf("%d", &(c[i][j]));
			}
		}
		printf("%d\n", solve());
	}

	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

const int MAX_H = 50;
const int MAX_W = 50;
int field[MAX_H][MAX_W];
int cnt;
int H, W;
// int dy[4] = {1, 0, -1, 0};
// int dx[4] = {1, 1, 0, -1};
bool seen[MAX_H][MAX_W];

void bfs(int y, int x)
{
    for (int dy = -1; dy <= 1; dy++)
    {
        for (int dx = -1; dx <= 1; dx++)
        {
            if (dy == 0 && dx == 0)
                continue;

            int ny = y + dy;
            int nx = x + dx;
            if (ny < 0 || ny >= H || nx < 0 || nx >= W)
                continue;
            if (field[ny][nx] == 0)
                continue;
            if (seen[ny][nx])
                continue;

            seen[ny][nx] = true;
            bfs(ny, nx);
        }
    }
}

int main()
{

    while (true)
    {
        cin >> W >> H;
        if (W == 0 && H == 0)
            break;

        for (int y = 0; y < H; y++)
        {
            for (int x = 0; x < W; x++)
            {
                cin >> field[y][x];
            }
        }

        cnt = 0;
        for (int y = 0; y < H; y++)
        {
            for (int x = 0; x < W; x++)
            {
                seen[y][x] = false;
            }
        }

        for (int y = 0; y < H; y++)
        {
            for (int x = 0; x < W; x++)
            {
                if (seen[y][x] || field[y][x] == 0)
                    continue;
                cnt++;
                seen[y][x] = true;
                bfs(y, x);
            }
        }

        cout << cnt << endl;
    }

    return 0;
}