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 <iostream>
#include <algorithm>
#include <vector>
#include <queue>
using namespace std;

typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<vi> vvi;

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

vvi t;
int W,H;

void dfs(int x,int y){
    t[x][y]='0';
    for(int i=0;i<8;i++){
        int nx = x + dx[i];
        int ny = y + dy[i];
        if(nx>=0 && nx<H && ny>=0 && ny<W && t[nx][ny]==1) dfs(nx,ny);
    }
    return;
}

int main(){
    while(cin>>W>>H){
        if(W==0&&H==0) return 0;

        t.resize(H);
        for(int i=0;i<H;i++) t[i].resize(W);

        for(int i=0;i<H;i++) for(int j=0;j<W;j++) cin>>t[i][j];

        int cnt=0;

        for(int i=0;i<H;i++) for(int j=0;j<W;j++) if(t[i][j]==1){
            cnt++;
            dfs(i,j);
        }
        cout << cnt << endl;
    }
}

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

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

void sol(int x, int y)
{
  field[x][y] = 0;
  for (int i = 0; i < 8; i++){
    if ((0 <= x + dx[i] && x + dx[i] < h) || (0 <= y + dy[i] && y + dy[i] < w))
    if (field[x + dx[i]][y + dy[i]] == 1) sol(x + dx[i], y + dy[i]);
  }
}

int main()
{

  while (cin >> h >> w, h || w){
    int res = 0;
    for (int i = 0; i < h; i++){
      for (int j = 0; j < w; j++){
        cin >> field[i][j];
      }
    }

    for (int i = 0; i < h; i++){
      for (int j = 0; j < w; j++){
        if (field[i][j] == 1){
          res++;
          sol(i, j);
        }
      }
    }
    cout << res << endl;
  }
}

C++: #include<bits/stdc++.h>
#include<iostream>
#define rep(i,n) for(int i=0;i<n;++i)
#define rrep(i,n) for(int i=n-1;i>=0;--i)
#define yesno(flg) if(flg){cout<<"YES"<<endl;}else{cout<<"NO"<<endl;}
#define MAX_N 1002
#define i197 1000000007

using namespace std;
typedef long long ll;
typedef pair<ll,ll> P1;
typedef pair<int,int> Pi;
typedef pair<double,Pi> Pdi;
typedef pair<ll,int>Pli;
typedef pair<int,ll>Pil;
typedef pair<P1,ll> P2;
typedef pair<string,string> Ps;
const ll INF=1000000000000000001;
struct edge{int to,cost;};
int dy[]={0, 0, 1, -1};
int dx[]={1, -1, 0, 0};
struct Road{double cost;int a,b;};
struct pos{
	// 1 変数を入れる;
	int x,y;
};

int main() {

	while(1){
		int w,h;
		cin>>w>>h;
		if(w==0&&h==0)return 0;
		int c[51][51]={},dp[51][51]={};
		rep(i,h)rep(j,w)cin>>c[j][i];

		int ans=0;
		rep(i,h){
			rep(j,w){
				if(c[j][i]==0||dp[j][i]==1)continue;
				ans++;
				queue<pos> que;
				pos pos1={j,i};
				que.push(pos1);
				dp[j][i]=1;
				while(!que.empty()){
					pos pos2=que.front();que.pop();
					if(dp[pos2.x+1][pos2.y]==0&&c[pos2.x+1][pos2.y]==1){
						pos pos3={pos2.x+1,pos2.y};
						dp[pos2.x+1][pos2.y]=1;
						que.push(pos3);
					}
					if(dp[pos2.x-1][pos2.y]==0&&c[pos2.x-1][pos2.y]==1){
						pos pos4={pos2.x-1,pos2.y};
						dp[pos2.x-1][pos2.y]=1;
						que.push(pos4);
					}
					if(dp[pos2.x][pos2.y+1]==0&&c[pos2.x][pos2.y+1]==1){
						pos pos5={pos2.x,pos2.y+1};
						dp[pos2.x][pos2.y+1]=1;
						que.push(pos5);
					}
					if(dp[pos2.x][pos2.y-1]==0&&c[pos2.x][pos2.y-1]==1){
						pos pos6={pos2.x,pos2.y-1};
						dp[pos2.x][pos2.y-1]=1;
						que.push(pos6);
					}
					if(dp[pos2.x+1][pos2.y-1]==0&&c[pos2.x+1][pos2.y-1]==1){
						pos pos7={pos2.x+1,pos2.y-1};
						dp[pos2.x+1][pos2.y-1]=1;
						que.push(pos7);
					}
					if(dp[pos2.x+1][pos2.y+1]==0&&c[pos2.x+1][pos2.y+1]==1){
						pos pos8={pos2.x+1,pos2.y+1};
						dp[pos2.x+1][pos2.y+1]=1;
						que.push(pos8);
					}
					if(dp[pos2.x-1][pos2.y+1]==0&&c[pos2.x-1][pos2.y+1]==1){
						pos pos9={pos2.x-1,pos2.y+1};
						dp[pos2.x-1][pos2.y+1]=1;
						que.push(pos9);
					}
					if(dp[pos2.x-1][pos2.y-1]==0&&c[pos2.x-1][pos2.y-1]==1){
						pos pos10={pos2.x-1,pos2.y-1};
						dp[pos2.x-1][pos2.y-1]=1;
						que.push(pos10);
					}
				}
			}
		}
		cout<<ans<<endl;
	}

	return 0;
}

C++: # include <iostream>

const int MAX_W = 50;
const int MAX_H = 50;

int w, h;

int c[MAX_H][MAX_W];

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

void dfs(int x, int y) {
	c[y][x] = 2;
	for (int i = 0; i < 8; ++i) {
		int nx = x + dx[i];
		int ny = y + dy[i];
		if (nx<0 || ny<0 || nx>w || ny>h)
			continue;
		if (c[ny][nx] == 1)
			dfs(nx, ny);
	}
}

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

int main() {
	while (1) {
		std::cin >> w >> h;
		if ((w + h) == 0)
			break;
		for (int i = 0; i < h; ++i) {
			for (int j = 0; j < w; ++j)
				std::cin >> c[i][j];
		}
		int res = solve();
		std::cout << res << std::endl;
	}
	return 0;
}