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>
using namespace std;
int w, h, isl, v;
int a[2501];
deque<int> Q;
int main()
{
	while(cin >> w >> h && w>0)
	{
		for(int i=1; i<=w*h; i++)
		{
			cin >> a[i];
		}
		isl=0;
		for(int i=1; i<=w*h; i++)
		{
			if(a[i]==1)
			{
				isl++;
				Q.clear();
				Q.push_back(i);
				while(!Q.empty())
				{
					v=Q.front();
					Q.pop_front();
					if(v>w)
					{
						if(a[v-w]==1)
						{
							a[v-w]=0;
							Q.push_back(v-w);
						}
						if(v%w!=1)
						{
							if(a[v-w-1]==1)
							{
								a[v-w-1]=0;
								Q.push_back(v-w-1);
							}
						}
					}
					if(v%w!=1)
					{
						if(a[v-1]==1)
						{
							a[v-1]=0;
							Q.push_back(v-1);
						}
					}
					if(v%w!=0)
					{
						if(v>w)
						{
							if(a[v-w+1]==1)
							{
								a[v-w+1]=0;
								Q.push_back(v-w+1);
							}
						}
						if(a[v+1]==1)
						{
							a[v+1]=0;
							Q.push_back(v+1);
						}
						if(v+w<w*h)
						{
							if(a[v+w+1]==1)
							{
								a[v+w+1]=0;
								Q.push_back(v+w+1);
							}
						}
					}
					if(v+w<=w*h)
					{
						if(v%w!=1)
						{
							if(a[v+w-1]==1)
							{
								a[v+w-1]=0;
								Q.push_back(v+w-1);
							}
						}
						if(a[v+w]==1)
						{
							a[v+w]=0;
							Q.push_back(v+w);
						}
					}
				}
			}
		}
		cout << isl << endl;
	}
	return 0;
}

C++: #include <stdio.h>
int map[100][100],n,m;
bool went[100][100];
void walk(int x,int y){
    if(x<0||y<0||x>=n||y>=m)return ;
    if(went[x][y])return ;
    if(map[x][y]==0)return ;
    went[x][y]=true;
    walk(x-1,y);
    walk(x+1,y);
    walk(x,y+1);
    walk(x,y-1);
    walk(x+1,y+1);
    walk(x+1,y-1);
    walk(x-1,y+1);
    walk(x-1,y-1);
    return ;
}
int main(){
    int ans;
    while(1){
        scanf("%d%d",&m,&n);
        if(n==0&&m==0)return 0;
        ans=0;
        for(int i=0;i<n;i++)for(int j=0;j<m;j++){
            scanf("%d",&map[i][j]);
            went[i][j]=false;
        }
        for(int i=0;i<n;i++)for(int j=0;j<m;j++)if(!went[i][j]&&map[i][j]==1){
            ans++;
            walk(i,j);
        }
        printf("%d\n",ans);
    }
}

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

using namespace std;


bool done[52][52];
int field[52][52];
int ofs[8][2] = {
  {0, 1},
  {1, 0},
  {-1, 0},
  {0, -1},
  {1, 1},
  {1, -1},
  {-1,-1},
  {-1, 1}
};

void paint(int y, int x)
{
  for (int i = 0; i < 8; ++i) {
    int nx = x + ofs[i][0];
    int ny = y + ofs[i][1];
    if (field[ny][nx] && !done[ny][nx]) {
      done[ny][nx] = true;
      paint(ny, nx);
    }
  }
}

int main() {
  int w, h;
  for(;;) {
    cin >> w >> h;
    if ((w|h) == 0) {
      break;
    }
    memset(field, 0, sizeof(field));
    memset(done, 0, sizeof(done));
    for (int i = 1; i <= h; ++i) {
      for (int j = 1; j <= w; ++j) {
        cin >> field[i][j];
      }
    }
    int cnt = 0;
    for (int i = 1; i <= h; ++i) {
      for (int j = 1; j <= w; ++j) {
        if (field[i][j] && !done[i][j]) {
          paint(i, j);
          ++cnt;
        }
      }
    }
    cout << cnt << endl;
  }
  return 0;
}