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 a[50][50];
void calc(int i,int j){
  if(a[i][j]==1){
    a[i][j]=2;
    calc(i+1,j);
    calc(i,j+1);
    calc(i+1,j+1);
    calc(i+1,j-1);
    calc(i-1,j);
    calc(i,j-1);
    calc(i-1,j-1);
    calc(i-1,j+1);
  }
  else return;
}

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

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

using namespace std;

#define PAIR pair<int, int>

int main() {
	int w, h;
	while (cin >> w >> h, w != 0 && h != 0) {
		bool field[52][52] = {{false}};

		for (int i = 1; i <= h; i++) {
			for (int j = 1; j <= w; j++) {
				cin >> field[i][j];
			}
		}

		stack<PAIR> st;
		int island = 0;
		int dx[] = {0, 1, 1, 1, 0, -1, -1, -1};
		int dy[] = { -1, -1, 0, 1, 1, 1, 0, -1};

		for (int i = 1; i <= h; i++) {
			for (int j = 1; j <= w; j++) {
				if (field[i][j]) {
					st.push(PAIR(i, j));
					while (!st.empty()) {
						int x = st.top().first;
						int y = st.top().second;
						st.pop();
						field[x][y] = false;
						for (int k = 0; k < 8; k++) {
							int nextX = x + dx[k];
							int nextY = y + dy[k];
							if (field[nextX][nextY]) {
								st.push(PAIR(nextX, nextY));
							}
						}
					}
					island++;
				}
			}
		}
		cout << island << endl;
	}
}

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

char c[102][102];

int mx, my;

void dfs(int x, int y){
    if(x < 0 || y < 0 || x >= mx || y >= my){
        return;
    }
    if(c[x][y] == '0'){
        return;
    }
    c[x][y] = '0';
    dfs(x+1, y);
    dfs(x+1, y+2);
    dfs(x+1, y-2);
    dfs(x-1, y);
    dfs(x-1, y+2);
    dfs(x-1, y-2);
    dfs(x, y+2);
    dfs(x, y-2);
    return;
}

int main(){
    int W, H, cnt = 0;
    scanf("%d %d\n", &W, &H);
    while(W != 0 || H != 0){
        mx = H;
        my = 2 * W;
        for(int k = 0; k < H; k++){
            cin.getline(c[k], sizeof(c[k]));
        }
        for(int i = 0; i < H; i++){
            for(int j = 0; j < 2 * W; j++){
                if(c[i][j] == '1'){
                    cnt++;
                    dfs(i, j);
                }
            }
        }
        cout << cnt << endl;
        scanf("%d %d\n", &W, &H);
        cnt = 0;
    }
}

C++: #include <iostream>
#include <algorithm>
#include <queue>
#include <array>
using namespace std;
typedef pair<int,int> P;

const array<int,8> dx={0,1,0,-1,1,1,-1,-1};
const array<int,8> dy={1,0,-1,0,1,-1,-1,1};
const int W=50;
const int H=50;

char M[H+1][W+1];

inline bool in_M(const int y,const int x){
    return (y>=0 && y<H && x>=0 && x<W);
}

void bfs(const int sy,const int sx){
    queue<P> que;

    que.push(P(sy,sx));
    M[sy][sx]='0';

    while(!que.empty()){
        P p=que.front();que.pop();

        for(int i=0;i<dx.size();i++){
            int ddy=p.first+dy[i],ddx=p.second+dx[i];
            if(in_M(ddy,ddx) && M[ddy][ddx]=='1'){
                que.push(P(ddy,ddx));
                M[ddy][ddx]='0';
            }
        }
    }
}

void solve(){
    int sum;
    int w,h;

    while(cin>>w>>h,w|h){
        cin.ignore();
        sum=0;

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

        for(int i=0;i<h;i++){
            for(int j=0;j<w;j++){
                if(M[i][j]=='1'){
                    bfs(i,j);
                    sum++;
                }
            }
        }

        cout<<sum<<endl;
    }
}

int main(){
    solve();
    return 0;
}

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];

#define OCTAS
#ifdef OCTAS
constexpr int dh[]{-1, -1, -1, 0, 0, +1, +1, +1};
constexpr int dw[]{-1, 0, +1, -1, +1, -1, 0, +1};
#else
constexpr int dh[]{-1, 0, 0, +1};
constexpr int dw[]{0, -1, +1, 0};
#endif

void dfs(int h, int w) {
  reached[h][w] = true;

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