Go: package main

import (
	"bufio"
	"fmt"
	"io"
	"os"
	"strconv"
)

const (
	initialBufSize = 100000
	maxBufSize     = 1000000
)

var sc *bufio.Scanner

func initScanner(r io.Reader) *bufio.Scanner {
	buf := make([]byte, initialBufSize)

	sc := bufio.NewScanner(r)
	sc.Buffer(buf, maxBufSize)
	sc.Split(bufio.ScanWords) // bufio.ScanLines
	return sc
}

func main() {
	sc = initScanner(os.Stdin)
	resolve()
}

func resolve() {
	results := []int{}
	for true {
		w, h := scanInt(sc), scanInt(sc)
		if w == 0 && h == 0 {
			break
		}
		grid := make([][]int, h)
		for i := 0; i < h; i++ {
			grid[i] = make([]int, w)
			for j := 0; j < w; j++ {
				grid[i][j] = scanInt(sc)
			}
		}
		num := 0
		for i := range loop0(h) {
			for j := range loop0(w) {
				start := pos{y: i, x: j}
				if grid[start.y][start.x] == 0 {
					continue
				}
				num++
				_dfs(grid, w, h, start)
			}
		}
		results = append(results, num)
	}
	for _, v := range results {
		fmt.Println(v)
	}
	return
}

func _dfs(grid [][]int, w, h int, start pos) {
	grid[start.y][start.x] = 0
	for _, df := range []pos{
		pos{1, 0}, pos{-1, 0},
		pos{0, -1}, pos{0, 1},
		pos{1, 1}, pos{-1, -1},
		pos{-1, 1}, pos{1, -1},
	} {
		np := addPos(start, df)
		if np.y < 0 || h <= np.y || np.x < 0 || w <= np.x {
			continue
		}
		if grid[np.y][np.x] == 0 {
			continue
		}
		_dfs(grid, w, h, np)
	}
}

type pos struct{ x, y int }

func addPos(p, d pos) pos {
	return pos{
		x: p.x + d.x,
		y: p.y + d.y,
	}
}

func loop0(n int) chan int {
	return loop(0, n-1, 1)
}

func loop1(n int) chan int {
	return loop(1, n, 1)
}

func loop(s, e, d int) chan int {
	ch := make(chan int)
	go func() {
		for i := s; i <= e; i += d {
			ch <- i
		}
		close(ch)
	}()
	return ch
}

// snip-scan-funcs
func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	i, _ := strconv.Atoi(sc.Text())
	return int(i)
}
func scanString(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

C++: 
/*
Problem

Category
DFS

URL:
http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=1160&lang=jp

考察:


Date: 2020/04/14
*/

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define int long long

/* ==== declarations ====== */
// functions
void solve();
void getInput();

// global variables
int w, h;
vector<vector<bool>> C;
vector<vector<int>> color;
int currentColor = 1;


/* ======================== */

signed main(){
    while(true){
        getInput();
        solve();
    }
    return 0;
}

void getInput() {
    cin>>w>>h;
    if(!w and !h) {exit(0);}
    C = vector<vector<bool>>(h, vector<bool>(w, false));
    color = vector<vector<int>>(h, vector<int>(w, 0));
    for(int i=0; i<h; i++) {
        for(int j=0; j<w; ++j) {
            bool c;
            cin>>c;
            C[i][j] = c;
        }
    }
}

void dfs(int i, int j) {
    if (i < 0 or j < 0 or i >= h or j >= w) return;
    if (!C[i][j]) return;
    if (color[i][j]) return;
    color[i][j] = currentColor;
    
    for(int a: {i-1, i, i+1})
        for(int b: {j-1, j, j+1})
            dfs(a, b);
    
}


void solve() {
    for(int i=0; i<h; i++) {
        for(int j=0; j<w; ++j) {
            dfs(i, j);
            currentColor++;
        }
    }
    set<int> colorSet {0};
    for(int i=0; i<h; i++) {
        for(int j=0; j<w; ++j) {
            colorSet.insert(color[i][j]);
        }
    }
    cout<<colorSet.size()-1<<endl;
}

C++: #include <iostream>

using namespace std;

// 0: 海, 1: 陸
int board[50][50] = {{0}};

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

bool DFS(int i, int j, int w, int h) {
  if (i < 0 || i >= h || j < 0 || j >= w) return false;
  if (!board[i][j]) return false;

  board[i][j] = 0;
  for (int d = 0; d < 8; ++d)
    DFS(i + dy[d], j + dx[d], w, h);

  return true;
}

int main() {
  for (;;) {
    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 >> board[i][j];
      }
    }

    int ans = 0;
    for (int i = 0; i < h; ++i) {
      for (int j = 0; j < w; ++j) {
        if (DFS(i, j, w, h)) ++ans;
      }
    }
    cout << ans << endl;
  }
  return 0;
}