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;

using ll = long long;

template<typename T> using V = std::vector<T>;
using Vi = V<int>;
using VVi = V<V<int>>;
using Vl = V<ll>;
using VVl = V<V<ll>>;
using Vs = V<string>;

template<typename T1, typename T2> using P = std::pair<T1, T2>;
using Pii = P<int, int>;
using Pll = P<ll, ll>;
using Pdd = P<double, double>;

template<typename T1, typename T2> using M = std::map<T1, T2>;
using Mii = M<int, int>;
using Msi = M<string, int>;

#define REP(i,n) for(int i=0;i<(int)(n);++i)
#define REP2(i,s,e) for(int i=(int)(s);i<(int)(e);++i)
#define RREP(i,s,e) for(int i=(int)(s);i>=(int)(e);--i)
#define FOR(i,c) for(__typeof((c).begin())i=(c).begin(),ie=(c).end();i!=ie;++i)
#define ALL(c) (c).begin(), (c).end()

const double PI = acos(-1);
const ll MOD = 1e9+7;

int n, w, h;
string s;
V<Pii> dir = {{1, 0}, {1, 1}, {1, -1}, {0, 1}, {0, -1}, {-1, 0}, {-1, 1}, {-1, -1}};

int main() {
    while (true) {
        cin >> w >> h;
        if (w == 0 && h == 0) {
            break;
        }

        VVi land(h, Vi(w));
        REP(i, h) REP(j, w) cin >> land[i][j];

        int res = 0;
        stack<Pii> s;
        while (true) {
            REP(i, h) {
                REP(j, w) {
                    if (land[i][j] == 1) {
                        s.push({i, j});
                        break;
                    }
                }
                if (!s.empty()) break;
            }
            if (s.empty()) break;

            res++;
            while (!s.empty()) {
                int y = s.top().first, x = s.top().second;
                s.pop();
                if (land[y][x] == 0) continue;
                land[y][x] = 0;
                FOR(i, dir) {
                    int Y = y + i->first, X = x + i->second;
                    if (Y < 0 || X < 0 || Y >= h || X >= w) continue;
                    if (land[Y][X] == 0) continue;
                    s.push({Y, X});
                }
            }
        }
        std::cout << res << '\n';
    }

    return 0;
}

C++: 
#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#include <vector>
#include <string>
#include <queue>
#include <algorithm>
#include <math.h>
#include <utility>
#include <set>
#include <map>
#define INF 100000
#define rep(i,n) for(int i =0;i<n;i++)
using namespace std;
typedef long long int ll;

#define MAX 5000

int G[51][51];
int h,w;


void dfs(int x, int y){
    /*for (int i=0; i<h; i++) {
        for (int j=0; j<w; j++) {
            cout <<G[i][j]<<" ";
        }
        cout << endl;
    }
    cout << endl;*/
    if(x<0||x>=h||y<0||y>=w) return;
    for (int i=-1; i<=1 ; i++) {
        if(x+i>=h or x+i<0) continue;
        for (int j=-1; j<=1; j++) {
            if(y+j>=w or y+j < 0) continue;
            if (G[x+i][y+j]==1) {
                G[x+i][y+j]=0;
                dfs(x+i,y+j);
            }
        }
    }
}


int main(){
    for(;;){
        cin >> w >> h;
        if(w==0 and h == 0) break;
        int ans=0;
        for (int i=0; i<h; i++) {
            for (int j=0; j<w; j++) {
                G[i][j]=0;
            }
        }
        for (int i = 0; i<h;i++) {
            for (int j=0; j < w; j++) {
                cin >> G[i][j];
            }
        }
        for (int i=0; i<h; i++) {
            for (int j=0; j<w; j++) {
                if (G[i][j]==1) {
                    G[i][j]=0;
                    ans++;
                    dfs(i,j);
                }
            }
        }
        cout << ans <<endl;
    }
    return 0;
}

C++: // AOJ 1160
#include<cstdio>
#define rep(i,a) for( int i = 0; i != (a); ++i )

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

int w, h;
bool c[50][50];

void dfs( int y, int x )
{
	c[y][x] = false;

	rep( i, 8 )
	{
		int nx = x+dx[i], ny = y+dy[i];

		if( nx >= 0 && nx < w && ny >= 0 && ny < h && c[ny][nx] )
			dfs( ny, nx );
	}

	return;
}

int main()
{
	while( scanf( "%d%d", &w, &h ), w|h )
	{
		rep( i, h )
			rep( j, w )
				scanf( "%d", &c[i][j] );

		int ans = 0;
		rep( i, h )
			rep( j, w )
				if( c[i][j] )
					dfs( i, j ), ++ans;

		printf( "%d\n", ans );
	}

	return 0;
}