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,a,n) for(int i=a;i<n;i++)
#define repr(i,a,n) for(int i=a;i>=n;i--)
#define INF 999999999
#define pb(a) push_back(a)

using namespace std;
typedef pair<int, int> pii;
typedef long long int ll;
typedef vector<pii> VP;

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

int w,h;

int dfs(int i, int j, int c[][51]) {
    if(c[i][j] == 1) {
        c[i][j] = 0;
        rep(di,i-1,i+2) {
            rep(dj,j-1,j+2) {
                if(di != i || dj != j) {
                    if(di<0 || di>=h || dj<0 || dj>=w) continue;
                    if(c[di][dj] == 1) dfs(di,dj,c);
                }
            }
        }
        return 1;
    }
    return 0;
}

int main() {
    int c[51][51];

    while(cin >> w >> h) {
        if(w == 0 && h == 0) break;

        rep(i,0,h) {
            rep(j,0,w) {
                cin >> c[i][j];
            }
        }

        int ret = 0;
        rep(i,0,h) {
            rep(j,0,w) {
                ret += dfs(i,j,c);
            }
        }

        cout << ret << endl;
    }
    return 0;
}

C++: #include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <cmath>

using namespace std;

using ll = long long;

#define REP(i,n) for(ll i=0;i<(ll)(n);i++)
#define REPD(i,n) for(ll i=n-1;i>=0;i--)
#define FOR(i,a,b) for(ll i=a;i<=(ll)(b);i++)
#define FORD(i,a,b) for(ll i=a;i>=(ll)(b);i--)

#define input(...) __VA_ARGS__; in(__VA_ARGS__)

template<class T>
void print(vector<T> a) {
  cout << "[ ";
  REP(i, a.size()) cout << a[i] << " ";
  cout << "]" << endl;
}

void print() {
  std::cout << std::endl;
}

template <class Head, class... Tail>
void print(Head&& head, Tail&&... tail) {
  std::cout << head << " ";
  print(std::forward<Tail>(tail)...);
}

void in() { }

template <class Head, class... Tail>
void in(Head&& head, Tail&&... tail) {
  cin >> head;
  in(std::forward<Tail>(tail)...);
}

vector<pair<ll, ll>> d = {
  {-1, -1},
  {+1, -1},
  {-1, +1},
  {+1, +1},
  {+0, +1},
  {+0, -1},
  {+1, +0},
  {-1, +0},
};

void dfs(ll x, ll y, vector<vector<ll>> &graph) {
  graph[y][x] = 0;
  for(auto v: d) {
    ll nx = v.first + x;
    ll ny = v.second + y;
    if (0 <= ny && ny < graph.size() && 0 <= nx && nx < graph[y].size() && graph[ny][nx]) {
      dfs(nx, ny, graph);
    }
  }
}

bool solve() {
  ll input(w, h);
  if (w == 0 && h == 0) return false;

  vector<vector<ll>> graph(h);
  REP(i, h) {
    vector<ll> r(w);
    REP(j, w) cin >> r[j];
    graph[i] = r;
  }

  ll cnt = 0;
  REP(i, h) REP(j, w) {
    if (graph[i][j]) {
      dfs(j, i, graph);
      cnt++;
    }
  }
  cout << cnt << endl;
  return true;
}

int main() {
  while (solve());
}

C++: #include<bits/stdc++.h>
#define LL long long
#define REP(i,n) for(int i=0;i<(n);++i)
#define REPA(i,n) for(int i=1;i<(n);++i)
#define foreach(i, n) for(auto &i:(n))
#define PII pair<int,int>
#define PLI pair<long long, int>
#define PLL pair<long long, long long>
#define PDD pair<double, double>
#define MOD ((int)1e9 + 7)
#define INF ((int)1e9)
#define INFLL ((LL)1e18)
#define ALL(x) (x).begin(),(x).end()
#define ctoi(x) (x - 'a') 
#define CTOI(x) (x - 'A')
#define BIT(x) (1 << (x))
using namespace std;

LL modinv(LL a){
    LL b = MOD, u = 1, v = 0;
    while(b){
        LL t = a / b;
        a -= t * b;swap(a, b);
        u -= t * v;swap(u, v);
    }
    u%=MOD;
    if(u < 0) u += MOD;
    return u;

}

LL exp(LL a, LL b){
    LL sum = a;
    LL res = 1;
    while(b){
        if(b&1){
            res = (res * sum)%MOD;
        }
        sum = (sum * sum) % MOD;
        b>>=1;
    }
    return res;
}

int N, M;
int mx[]={1, 1, 1, 0, -1, -1, -1, 0}, my[]={1, 0, -1, -1, -1, 0, 1, 1};

int main(){
    while(cin>>M>>N&&N){
        vector<vector<int> > m(N+2, vector<int>(M+2, 0));
        REPA(i, N+1){
            REPA(j, M+1){
                cin >> m[i][j];
            }
        }
        int ans = 0;
        REPA(i, N+1){
            REPA(j, M+1){
                if(!m[i][j])continue;
                ++ans;
                queue<PII> que;
                que.push(PII(i, j));
                m[i][j]=0;
                while(!que.empty()){
                    PII d = que.front();
                    que.pop();
                    REP(i, 8){
                        int nx = d.first + mx[i];
                        int ny = d.second + my[i];
                        if(!m[nx][ny])continue;
                        m[nx][ny]=0;
                        que.push(PII(nx, ny));
                    }
                }
            }
        }
        cout << ans << endl;
    }
    return 0;
}