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<vector>
#include <unordered_map>
#include <algorithm>
#include <functional>
#include <map>
#include <string>
#include <sstream>
#include <cmath>
#include <float.h>
using namespace std;



bool checked[50][50];
int island[50][50];
int count1 = 0;
int w, h;
vector<int> num;
unsigned long long int mod = 1000000007;

void checkIsland(int x, int y) {
    if (x < 0 || x >= h || y >= w || y < 0) { return; }
    if (!island[x][y] || checked[x][y]) {
        checked[x][y] = true;
        return;
    }
    checked[x][y] = true;
    checkIsland(x + 1, y);
    checkIsland(x + 1, y + 1);
    checkIsland(x + 1, y - 1);
    checkIsland(x, y + 1);
}

void runtime() {
    count1 = 0;
    for (int i = 0; i < w; ++i) {
        for (int j = 0; j < h; ++j) {
            checked[i][j] = false;
            cin >> island[i][j];
        }
    }
    for (int i = 0; i < w; ++i) {
        for (int j = 0; j < h; ++j) {
            if (checked[i][j]) continue;
            if (island[i][j]) {
                count1++;
                checkIsland(i, j);
            }
            else {
                checked[i][j] = true;
            }
        }
    }
    num.push_back(count1);
}


int main() {
    cin >> w >> h;
    while (!(w == 0 && h == 0)) {
        runtime();
        cin >> w >> h;
    }
    for (auto i : num) {
        cout << i << endl;
    }
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
using ll=long long;
typedef pair<int,int> P;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
int main(){
    int w,h;
    cin>>w>>h;
    vector<vector<int>>G(h,vector<int>(w));
    queue<P> Q;
    for(int i=0;i<h;i++){
        for(int j=0;j<w;j++){
            cin>>G.at(i).at(j);
        }
    }
    int count=0,x,y,nx,ny;
    P p;
    for(int i=0;i<h;i++){
        for(int j=0;j<w;j++){
            if(G.at(i).at(j)==1){
            Q.push(P(i,j));
            while(!Q.empty()){
        p=Q.front();
        Q.pop();
        x=p.first;
        y=p.second;
        G.at(x).at(y)=0;
            for(int i=-1;i<=1;i++){
        for(int j=-1;j<=1;j++){
            nx=x+i;
            ny=y+j;
        if(0<=nx&& nx<h && 0<=ny&& ny<w && G.at(nx).at(ny)==1) Q.push(P(nx,ny));
        }
    }
    }
    count++;
    }
    }
    }
cout<<count<<endl;
}

C++: #include <stdio.h>

int w, h;
int island[50][50], map[50][50], ans;

void dfs(int x, int y, int flg) {
		int i, j;
	if(x < 0 || w <= x || y < 0 || h <= y || map[x][y] == 1) {
		return;
	}
	else if(map[x][y] == 0) {
		if(island[y][x] == 0) {
			if(flg == 0) {
			 	map[x][y] = 1;
		
				for(i = -1; i <= 1; i ++) {
					for(j = -1; j <= 1; j ++) {
						dfs(x + i, y + j, 0);
					}
				}
			}
			else if(flg == 1) {
				return;
			}
		}
		else if(island[y][x] == 1) {
			map[x][y] = 1;  
					
			if(flg == 0) {
				ans ++; 
			}
			for(i = -1; i <= 1; i ++) {
				for(j = -1; j <= 1; j ++) {
					dfs(x + i, y + j, 1);
				}
			}
		}
	}
	return;
}

int main() {
	
	int i, j;
	while(scanf("%d %d", &w, &h)) {
		if(w == 0 && h == 0) { break; }
		
		ans = 0;
		for(i = 0; i < 50; i ++) {
			for(j = 0; j < 50; j ++) {
				map[i][j] = -1;
				island[i][j] = 0;
			}
		}
	
		for(i = 0; i < h; i ++) {
			for(j = 0; j < w; j ++) {
				scanf("%d", &island[i][j]);
				map[i][j] = 0;
			}
		}
		
		for(i = 0; i < h; i ++) {
			for(j = 0; j < w; j ++) {
				dfs(i, j, 0);
			}
		}
		printf("%d\n", ans);
	}

	return 0;
}

C++: #include <iostream>
#include <ios>
#include <iomanip>
#include <algorithm>
#include <string>
#include <vector>
#include <map>
#include <set>
#include <cstdlib>
#include <cstring>
#include <cmath>
using namespace std;

#define MOD 1e9+7
#define INF 1e9+7
#define rep(i, n) for(int i=0; i<n; ++i)
typedef long long ll;

#define MAX_N 100000
#define MAX_V 100
#define MAX_E 100

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

int ddx[] = {-1, 0, 1, 0, -1, 1, -1, 1};
int ddy[] = {0, -1, 0, 1, 1, 1, -1, -1};

//--------------------------

void dfs(int x, int y);

int w, h, cnt;

int c[50][50];

int main() {

  while(true) {
    cin >> w >> h;

    if(w==0&&h==0) break;

    cnt = 0;

    rep(i, h) {
      rep(j, w) cin >> c[i][j];
    }

    rep(i, h) {
      rep(j, w) {
        if(c[i][j]==1) {
          dfs(i, j);
          ++cnt;
        }
      }
    }

    cout << cnt << endl;
  }

  return 0;
}

void dfs(int x, int y) {

  if(x<0||x>=h||y<0||y>=w||c[x][y]==0) {
    return;
  }

  c[x][y] = 0;

  rep(i, 8) {
    dfs(x+ddx[i], y+ddy[i]);
  }
}