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++: #define _crt_secure_no_warnings

#ifndef _GLIBCXX_NO_ASSERT
#include <cassert>
#endif
#include <cctype>
#include <cerrno>
#include <cfloat>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>

#ifdef __GXX_EXPERIMENTAL_CXX0X__
#include <ccomplex>
#include <cfenv>
#include <cinttypes>
#include <cstdbool>
#include <cstdint>
#include <ctgmath>
#include <cwchar>
#include <cwctype>
#endif


#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>

#ifdef __GXX_EXPERIMENTAL_CXX0X__
#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <system_error>
#include <thread>
#include <tuple>
#include <typeindex>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#endif

using namespace std;

vector<vector<int>>data;

int x[] = { 0, 1, 1, 1, 0, -1, -1, -1 };
int y[] = { 1, 1, 0, -1, -1, -1, 0, 1 };

void serch(int i, int j)
{
	data[i][j] = 0;
	for (size_t k = 0; k < 8; k++)
	{
		if (data[i + x[k]][j + y[k]])
		{
			serch(i + x[k], j + y[k]);
		}
	}
}

int main()
{
	int N, M;
	int ans = 0;
	while (1)
	{
		data.clear();
		ans = 0;
		cin >> N >> M;
		if (N == 0 && M == 0)break;
		swap(M, N);
		data.resize(N + 2);
		for (size_t i = 0; i < N + 2; i++)
		{
			data[i].resize(M + 2);
			for (size_t j = 0; j < M+2; j++)
			{
				data[i][j] = 0;
			}
		}
		for (size_t i = 1; i <= N; i++)
		{
			for (size_t j = 1; j <= M; j++)
			{
				cin >> data[i][j];
			}
		}
		for (size_t i = 1; i <= N; i++)
		{
			for (size_t j = 1; j <= M; j++)
			{
				if (data[i][j])
				{
					ans++;
					serch(i, j);
				}
			}
		}
		cout << ans<<endl;
	}
}

C++: #include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define rep(i,n) FOR(i,0,n)
#define repr(i,n) for(int i=(n)-1;0<=i;--i)
#define each(e,v) for(auto&& e:(v))
#define all(v) begin(v),end(v)
#define dump(x) cerr<<#x<<": "<<(x)<<endl
#define INF 100000000
#define IINF 9999999999999;
using vint = vector<int>;
using ll = long long;
using vll = vector<ll>;
template <class T> void chmin(T& a, const T& b) { a = min(a, b); }
template <class T> void chmax(T& a, const T& b) { a = max(a, b); }

int prime[25] = {2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97};
long long int dp[101][20] = {0};

bool earth[51][51];

void erase_island(int h, int w) {
    earth[h][w] = false;
    //cout << "# " << h << " " << w << endl;
    if(earth[h - 1][w - 1]) erase_island(h - 1, w - 1);
    if(earth[h - 1][w]) erase_island(h - 1, w);
    if(earth[h - 1][w + 1]) erase_island(h - 1, w + 1);
    if(earth[h][w + 1]) erase_island(h, w + 1);
    if(earth[h + 1][w + 1]) erase_island(h + 1, w + 1);
    if(earth[h + 1][w]) erase_island(h + 1, w);
    if(earth[h + 1][w - 1]) erase_island(h + 1, w - 1);
    if(earth[h][w - 1]) erase_island(h, w - 1);
}

int main() {
    int w, h;
    cin >> w >> h;
    rep(i, h) rep(j, w) {
        int temp;
        cin >> temp;
        if(temp == 0) earth[i][j] = false;
        else earth[i][j] = true;
    }

    int ans = 0;
    rep(i, h) rep(j, w) {
        if(earth[i][j]) erase_island(i , j), ++ans;
    }

    cout << ans << endl;
}

C++: #include <bits/stdc++.h>
#define rep(i,n) for (int i=0; i<(n); ++i)
using namespace std;

int h,w;
vector < vector <int> >c;

int dy[8]={-1,-1,-1,0,0,1,1,1};
int dx[8]={-1,0,1,-1,1,-1,0,1};

void dfs(int i, int j){
    c[i][j]=0;
    rep(dir,8){
        int vy=i+dy[dir];
        int vx=j+dx[dir];
        if(vy>=0&&vy<h&&vx>=0&&vx<w&&c[vy][vx]==1){
            dfs(vy,vx);
        }
    }
    return;
}

int main(){
    while(1){
        cin >> w >> h;
        if(h==0&&w==0)break;
        c = vector <vector <int> >(h, vector <int> (w) );
        rep(i,h)rep(j,w)cin >> c[i][j];
        int cnt=0;
        rep(i,h)rep(j,w){
            if(c[i][j]==1){
                dfs(i,j);
                cnt++;
            }
        }
        cout << cnt << endl;
    }
    return 0;
}