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 <stdio.h>
#include <stack>

#define MAX_W 50
#define MAX_H 50
#define LAND 1
#define SEA 0
int map[MAX_H][MAX_W];
int h, w;
using namespace std;
stack<int> x, y;

bool input() {
  int i, j;

  scanf("%d %d", &w, &h);
  if (w == 0 && h == 0) return false;
  for (i = 0; i < h; i++) {
    for (j = 0; j < w; j++) {
      scanf("%d", &map[i][j]);
    }
  }

  return true;
}

int main() {
  int i, j, cnt;

  while (input()) {
    cnt = 0;
    for (i = 0; i < h; i++) {
      for (j = 0; j < w; j++) {
        if (map[i][j] == LAND) {
          cnt++;
          x.push(j);
          y.push(i);
          while (!x.empty() && !y.empty()) {
            int a = x.top();
            x.pop();
            int b = y.top();
            y.pop();
            if (a < 0 || w <= a || b < 0 || h <= b || map[b][a] == SEA)
              continue;
            map[b][a] = SEA;
            x.push(a - 1);
            y.push(b - 1);
            x.push(a - 1);
            y.push(b);
            x.push(a - 1);
            y.push(b + 1);
            x.push(a);
            y.push(b - 1);
            x.push(a);
            y.push(b + 1);
            x.push(a + 1);
            y.push(b - 1);
            x.push(a + 1);
            y.push(b);
            x.push(a + 1);
            y.push(b + 1);
          }
        }
      }
    }
    printf("%d\n", cnt);
  }

  return 0;
}

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

void input(int **, int, int);
int howManyIslands(int **, int, int);
void howBigIslands(int **, bool **, int, int, int, int);

int main()
{
	int **island, w, h;
	while(true){
		cin >> w >> h;
		if(w==h && h==0) break;
		island = new int*[w];
		for(int i=0; i<w; i++)
			island[i] = new int[h];
		input(island, w, h);
		cout << howManyIslands(island, w, h) << endl;
		for(int i=0; i<w; i++)
			delete[] island[i];
		delete[] island;
	}
	return 0;
}

void input(int **island, int w, int h)
{
	char buf[60];
	cin.clear();cin.ignore();
	for(int i=0; i<h; i++){
		cin.getline(buf, sizeof(buf));
		int j=0, k=0;
		while(buf[j] != '\0'){
			if(buf[j] != ' '){
				switch(buf[j]){
				case '0':
					island[k][i] = 0;
					k++;
					break;
				case '1':
					island[k][i] = 1;
					k++;
					break;
				}
				if(w==k) break;
			}
			j++;
		}
	}
}

int howManyIslands(int **island, int w, int h)
{
	bool **check;
	int ans = 0;
	check = new bool*[w];
	for(int i=0; i<w; i++){
		check[i] = new bool[h];
		for(int j=0; j<h; j++)
			check[i][j] = false;
	}
	for(int i=0; i<w; i++){
		for(int j=0; j<h; j++){
			if(check[i][j])continue;
			if(island[i][j]){
				ans++;
				howBigIslands(island, check, i, j, w, h);
			} else {
				check[i][j] = true;
			}
		}
	}
	for(int i=0; i<w; i++)
		delete[] check[i];
	delete[] check;

	return ans;
}

void howBigIslands(int **island, bool **check, int x, int y, int w, int h)
{
	if(check[x][y]) return;
	enum __DIR{ UPPER_LEFT, UP, UPPER_RIGHT, LEFT, RIGHT, LOWER_LEFT,
		UNDER, LOWER_RIGHT, DIR_END};
	int periphe[DIR_END][2]={
			{-1, -1}, {0, -1}, {1, -1},
			{-1, 0}, {1, 0},
			{-1, 1}, {0, 1}, {1, 1}
	};
	check[x][y] = true;
	for(int i=0; i<DIR_END; i++){
		if(x+periphe[i][0] < 0 || w-1 < x+periphe[i][0] ||
			y+periphe[i][1] < 0 || h-1 < y+periphe[i][1]) continue;
		if(island[x+periphe[i][0]][y+periphe[i][1]]){
			if(!check[x+periphe[i][0]][y+periphe[i][1]])
				howBigIslands(island, check,
				x+periphe[i][0], y+periphe[i][1], w, h);
		}
	}
}

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

int main(void){
	int w, h;
	int dx[] = {1,1,0,-1,-1,-1,0,1};
	int dy[] = {0,1,1,1,0,-1,-1,-1};
	while(true){
		cin >> w >> h;
		if(!w&&!h)break;
		vector<int> c[h+2];
		c[0].resize(w+2);
		c[h+1].resize(w+2);
		for(int i = 1; i <= h; ++i){
			c[i].resize(w+2);
			for(int j = 1; j <= w; ++j){
				cin >> c[i][j];
			}
		}
		int ans = 0;
		queue<pair<int, int>> q;
		for(int i = 1; i <= h; ++i){
			for(int j = 1; j <= w; ++j){
				if(c[i][j] == 1){
					q.emplace(i,j);
					ans++;
					c[i][j] = 0;
					while(!q.empty()){
						int x = q.front().first;
						int y = q.front().second;
						q.pop();
						for(int dir = 0; dir < 8; ++dir){
							int nx = x + dx[dir];
							int ny = y + dy[dir];
							if(c[nx][ny]==1){
								q.emplace(nx,ny);
								c[nx][ny]=0;
							}
						}
					}
				}
			}
		}
		cout << ans << endl;
	}
	return 0;
}