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<stdio.h>
#include<cstring>
#include<math.h>
#include<map>
#include<bitset>
#include<iomanip>
using namespace std;

#define rep(i, n) for (int i = 0; i < (int)(n); ++i)
int w, h;
int m[50][50];
int visited[50][50] = {0};

void dfs(int x, int y) {
  visited[x][y] = 1;
  for(int i = -1; i <= 1; i++) {
    for(int j = -1; j <= 1; j++) {
      int nx = x + i;
      int ny = y + j;
      if(0 <= nx && nx < h && 0 <= ny && ny < w && visited[nx][ny] == 0 && m[nx][ny] == 1) {
        dfs(nx, ny);
      }
    }
  }
  
}

int main() {
  while(true) {
    rep(i, h) {
      rep(j, w) {
        visited[i][j] = 0;
      }
    }
    cin >> w >> h;
    if(w == 0 && h == 0) break;
    rep(i, h) {
      rep(j, w) {
        cin >> m[i][j];
      }
    }
    int count = 0;
    for(int i = 0; i < h; i++) {
      for(int j = 0; j < w; j++) {
        if(m[i][j] == 1 && visited[i][j] == 0) {
          count++;
          dfs(i, j);
        }
      }
    }
    cout << count << endl;
  }
  return 0;
}

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

int H, W;
bool grid[55][55];

void island(int h, int w) {
  grid[h][w] = 0;

  for(int i = -1; i <= 1; ++i) {
    for(int j = -1; j <= 1; ++j) {
      if(i == 0 && j == 0) continue;
      int nh = h + i;
      int nw = w + j;
      if(0 <= nh && nh < H && 0 <= nw && nw < W && grid[nh][nw]) island(nh, nw);
    }
  }
}

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

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

    int ans = 0;
    for(int i=0; i < H; ++i) {
      for(int j=0; j < W; ++j) {
        if(grid[i][j]) {
          island(i,j);
          ++ans;
        }
      }
    }
    cout << ans << '\n';
  }

  return 0;
}

C++: #include <algorithm>
#include<iostream>
#include<vector>
#include<list>
#include<map>
#include<set>
#include<string>

#include<stdlib.h>
#include<string.h>
#include<math.h>
#include<limits.h>

using namespace std;

long mapp[51][51];
bool seen[51][51];
int W,H;

// 八方向への移動ベクトル
const int dx[8] = {1, 0, -1, 0, -1, 1 ,-1, 1};
const int dy[8] = {0, 1, 0, -1, -1,-1 , 1, 1};

void dfs(int w,int h){

  seen[h][w] = true;
  int ii,jj;
  int nx,ny;

  for(ii=0;ii<8;ii++){

    nx = w + dx[ii];
    ny = h + dy[ii];

    if(nx < 0 || ny < 0 || nx >= W || ny >= H){continue;}
    if(mapp[ny][nx] == 0){continue;}
    if(seen[ny][nx] == true){continue;}

    //cout << "H:" << H << "W:" << W << "nx:" << nx << "ny:" << ny << endl;
    dfs(nx,ny);
  }

  
}

int main(){

  long ii,jj,kk;
  vector<int> ret;


  while(true){
    cin >> W >> H;
    //cout << "W:" << W << "H:" << H <<endl;
    if(W == 0){
      break;
    }
    memset(mapp,0,sizeof(mapp));    
    for(ii=0;ii<H;ii++){
      for(jj=0;jj<W;jj++){
        cin >> mapp[ii][jj];
      }
    }

    memset(seen,0,sizeof(seen));

    int cnt=0;

    for(ii=0;ii<H;ii++){
      for(jj=0;jj<W;jj++){

        //cout << "ii:" << ii << "jj:" << jj << endl;
        if(mapp[ii][jj] == 1 && seen[ii][jj] == false){
          //cout << "ii:" << ii << "jj:" << jj << endl;
          dfs(jj,ii);
          cnt++;
        }
      }
    }

    cout << cnt << endl;
  }
  
  return 0;
}

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

using namespace std;

void dfs(vector<vector<int> >& map, int y, int x, int H, int W, int index)
{
  int dx[8] = {-1, 0, 1, -1, 1, -1, 0, 1};
  int dy[8] = {-1, -1, -1, 0, 0, 1, 1, 1};

  map[y][x] = index;
  for (int i = 0; i < 8; i++)
  {
    if (y + dy[i] >= 0 && y + dy[i] < H && x + dx[i] >= 0 && x + dx[i] < W){
      if (map[y + dy[i]][x + dx[i]] == 1)
      {
        dfs(map, y + dy[i], x + dx[i], H, W, index);
      }
    }
  }
}

int main()
{
  int W,H;
  int index = 2;
  while(1){
    cin >> W >> H;
    if(W == 0 && H == 0){
      break;
    }
    vector<vector<int> > map(H, vector<int>(W, 0));
    for (int i = 0; i < H; i++)
    {
      for (int j = 0; j < W;j++){
        cin >> map[i].at(j);
      }
    }
    for (int i = 0; i < H;i++){
      for (int j = 0; j < W;j++){
        if(map[i][j] == 1){
          dfs(map, i, j, H, W, index);
          index++;
        }
      }
    }

    cout << index - 2 << endl;
    index = 2;
    map.clear();
  }
  return 0;
}