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>

#define REP(i, n) for(int (i)=0; (i)<(n); (i)++)
#define ALL(v) (v).begin(), (v).end()
#define INF 1e9

using namespace std;
typedef pair<int, int> pii;

int w, h;
int m[50][50];
int dx[8] = {1, 1, 1, 0, 0, -1, -1, -1};
int dy[8] = {-1, 0, 1, -1, 1, -1, 0, 1};

void dfs(int nw, int nh){
  REP(i, 8){
    if(nw + dx[i] < 0 or nw + dx[i] >= w or nh + dy[i] < 0 or nh + dy[i] >= h) continue;
    if(m[nw+dx[i]][nh+dy[i]] == 1) { m[nw+dx[i]][nh+dy[i]] = 0; dfs(nw+dx[i], nh+dy[i]); }
  }
  return;
}

int main(){
  while(cin >> w >> h and w + h){
    int res = 0;
    REP(i, h) REP(j, w) cin >> m[j][i];
    REP(i, h) REP(j, w) { if(m[j][i]) { dfs(j, i); res++; } }
    cout << res << endl;
  }
  return 0;
}

C++: #include<iostream>
#include<queue>
#include<algorithm>

using namespace std;

void sink(int i, int j,int w,int h, int** field);

int main() {
	int w, h;
	int** field;
	while (1) {
		cin >> w >> h;
		if (w == 0)break;
		field = new int* [h];
		for (int i = 0;i < h;i++) {
			field[i] = new int[w];
			for (int j = 0;j < w;j++) {
				cin >> field[i][j];
			}
		}
		int cnt = 0;
		for (int i = 0;i < h;i++) {
			for (int j = 0;j < w;j++) {
				if (field[i][j]) {
					cnt++;
					sink(i, j,w,h, field);
				}
			}
		}
		cout << cnt << endl;
	}
}

void sink(int i, int j,int w,int h, int** field) {
	field[i][j] = 0;
	if (i > 0) {
		if (field[i - 1][j])sink(i - 1, j, w, h, field);
	}
	if (i < h-1) {
		if (field[i + 1][j])sink(i + 1, j, w, h, field);
	}
	if (j > 0) {
		if (field[i][j-1])sink(i , j-1, w, h, field);
	}
	if (j < w-1) {
		if (field[i][j+1])sink(i , j+1, w, h, field);
	}
	if (i > 0 && j > 0) {
		if (field[i - 1][j - 1])sink(i - 1, j - 1, w, h, field);
	}
	if (i > 0 && j < w - 1) {
		if (field[i - 1][j + 1])sink(i - 1, j + 1, w, h, field);
	}
	if (i < h-1 && j > 0) {
		if (field[i + 1][j - 1])sink(i + 1, j - 1, w, h, field);
	}
	if (i < h-1 && j < w-1) {
		if (field[i + 1][j + 1])sink(i + 1, j + 1, w, h, field);
	}
}

C++: #include <algorithm>
#include <cstdio>
#include <iostream>
#include <map>
#include <cmath>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
#include <stdlib.h>
#include <stdio.h>
#include <bitset>
using namespace std;
#define FOR(I,A,B) for(int I = (A); I < (B); ++I)
#define CLR(mat) memset(mat, 0, sizeof(mat))
typedef long long ll;
int W, H;
int c[50][50];
bool visited[50][50];
int vy[8] = {-1,-1,0,1,1,1,0,-1};
int vx[8] = {0,1,1,1,0,-1,-1,-1};
void calc(int y, int x) {
  if(y < 0 || y >= H || x < 0 || x >= W) return;
  if(visited[y][x] || c[y][x] == 0) return;
  visited[y][x] = true;
  FOR(i,0,8) calc(y+vy[i],x+vx[i]);
  return;
}
int main()
{
  while(cin >> W >> H, (W || H)) {
    CLR(visited);
    FOR(y,0,H) FOR(x,0,W) cin >> c[y][x];
    int ans = 0;
    FOR(y,0,H) {
      FOR(x,0,W) {
        if(visited[y][x] || c[y][x] == 0) continue;
        calc(y, x);
        ans++;
      }
    }
    cout << ans << endl;
  }
  return 0;
}

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

int w, h;
bool state[51][51];

int dx[8] = { 0, 1, 0,-1, 1, 1,-1,-1};
int dy[8] = { 1, 0,-1, 0, 1,-1, 1,-1};

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

void dfs(int x, int y){
    state[x][y] = 0;
    
    for(int i = 0; i < 8; i++){
        int nx = x + dx[i], ny = y + dy[i];
        if(isRegion(nx, ny) && state[nx][ny]){
            dfs(nx, ny);
        }
    }
}

int main(int argc, const char * argv[]) {
    while(1){
        cin >> w >> h;
        if(!w && !h) break;
        for(int y = 0; y < h; y++){
            for(int x = 0; x < w; x++){
                cin >> state[x][y];
            }
        }
        
        int cnt = 0;
        for(int y = 0; y < h; y++){
            for(int x = 0; x < w; x++){
                if(state[x][y]){
                    dfs(x, y);
                    cnt++;
                }
            }
        }
        cout << cnt << endl;
    }
}