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>
using namespace std;

constexpr int MAX_H = 55;
constexpr int MAX_W = 55;

int H, W;
int grid[MAX_H][MAX_W];
bool reached[MAX_H][MAX_W];

int dh[8] = {-1, -1, -1,  0,  0,  1,  1,  1};
int dw[8] = {-1,  0,  1, -1,  1, -1,  0,  1};

void dfs(int h, int w) {
  reached[h][w] = true;
  for (int i{}; i < 8; ++i) {
    int nh = h + dh[i];
    int nw = w + dw[i];
    if (nh < 0 || nh >= H || nw < 0 || nw >= W ||
        reached[nh][nw] || grid[nh][nw] == 0)
      continue;
    dfs(nh, nw);
  }
}

int main() {
  while (true) {
    cin >> H >> W;
    if (H == 0 && W == 0)
      break;
    for (int h{}; h < H; ++h) {
      for (int w{}; w < W; ++w) {
        reached[h][w] = false;
        cin >> grid[h][w];
      }
    }

    int island{};
    for (int h{}; h < H; ++h) {
      for (int w{}; w < W; ++w) {
        if (grid[h][w] == 0 || reached[h][w])
          continue;
        dfs(h, w);
        ++island;
      }
    }

    cout << island << endl;
  }

  return 0;
}

C++: #include <iostream>
using namespace std;

int myMap[50][50];
int w, h;
int ans;

bool safe(int x, int y){
    return (0 <= x && 0 <= y) && (x < w && y < h);
}

void del(int x, int y){
    myMap[x][y] = 0;
    if (safe(x+1, y) && myMap[x+1][y]) del(x+1, y);
    if (safe(x+1, y+1) && myMap[x+1][y+1]) del(x+1, y+1);
    if (safe(x+1, y-1) && myMap[x+1][y-1]) del(x+1, y-1);
    if (safe(x, y+1) && myMap[x][y+1]) del(x, y+1);
    if (safe(x, y-1) && myMap[x][y-1]) del(x, y-1);
    if (safe(x-1, y-1) && myMap[x-1][y-1]) del(x-1, y-1);
    if (safe(x-1, y+1) && myMap[x-1][y+1]) del(x-1, y+1);
    if (safe(x-1, y) && myMap[x-1][y]) del(x-1, y);
    return;
}

int main(){

    while (1){
	cin >> w >> h;
	if (w == 0 && h == 0) break;

	for (int i = 0; i < w; i++){
	    for (int j = 0; j < h; j++){
		cin >> myMap[i][j];
	    }
	}

	ans = 0;	
	for (int i = 0; i < w; i++){
	    for (int j = 0; j < h; j++){
		if (myMap[i][j] == 1) {
		    ans++;
		    del(i, j);
		}
	    }
	}

	cout << ans << endl;
    }
    
}

C++: #include<iostream>
#include<cmath>
#include<cstdio>
#include<algorithm>
#include<vector>
#include<cstring>

using namespace std;

#define INF 999999999

int map[52][52];
bool ch[52][52];
int ans;

void dfs(int map[52][52], bool c[52][52], int x, int y){
	//cout << x << " " << y << " " << ans << endl;
	c[x][y] = 1;
	if(map[x-1][y]==1 && c[x-1][y]==0) dfs(map,c,x-1,y);
	if(map[x-1][y-1]==1 && c[x-1][y-1]==0) dfs(map,c,x-1,y-1);
	if(map[x-1][y+1]==1 && c[x-1][y+1]==0) dfs(map,c,x-1,y+1);
	if(map[x+1][y]==1 && c[x+1][y]==0) dfs(map,c,x+1,y);
	if(map[x-1][y-1]==1 && c[x-1][y-1]==0) dfs(map,c,x-1,y-1);
	if(map[x-1][y+1]==1 && c[x-1][y+1]==0) dfs(map,c,x-1,y+1);
	if(map[x][y-1]==1 && c[x][y-1]==0) dfs(map,c,x,y-1);
	if(map[x][y+1]==1 && c[x][y+1]==0) dfs(map,c,x,y+1);
}

int main(){
	int i, j, w, h;
	while(1){
		cin >> w >> h;
		if(!w) break;
		for(i=0;i<=h+1;i++){
			for(j=0;j<=w+1;j++){
				if(i==0||i==h+1||j==0||j==w+1)map[i][j]=0;
				else cin >> map[i][j];
				ch[i][j] = 0;
			}
		}
		ans = 0;
		for(i=1;i<=h;i++){
			for(j=1;j<=w;j++){
				if(map[i][j]&&!ch[i][j]){
					dfs(map,ch,i,j);
					ans++;
				}
			}
		}
		
		cout << ans << endl;
	}
	return 0;
}

C++: #include <iostream>
using namespace std;
int h,w;
int G[1000][1000];
int dx[] = {-1,0,1,-1,1,-1,0,1},dy[] = {-1,-1,-1,0,0,1,1,1};

void dfs(int px,int py){
  G[px][py] = 0;
  for(int i = 0 ; i < 8 ; i++ ){
    int nx = px + dx[i],ny = py + dy[i];
    if(0 <= nx && nx < w && 0 <= ny && ny < h && G[nx][ny] == 1){
      dfs(nx,ny);
    }
  }
}

int main(){
  while( cin >> w >> h,w+h){

    for(int i = 0 ; i < h ; i++){
      for(int j = 0 ; j < w ; j++){
	cin >> G[j][i];
      }
    }

    int cnt = 0;
    for(int i = 0 ; i < h ; i++){
      for(int j = 0 ; j < w ; j++){
	if(G[j][i] == 1){
	  dfs(j,i);
	  cnt++;
	}
      }
    }
    cout << cnt << endl;
  }
  return 0;
}