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++: #define _CRT_SECURE_NO_WARNINGS
#include"bits/stdc++.h"
#define INF          1e9
#define INFLL        1e18
#define EPS          1e-9
#define MOD          1000000007
#define REP(i,n)     for(ll i=0,i##_len=(n);i<i##_len;++i)
#define REP1(i,n)    for(ll i=1,i##_len=(n);i<=i##_len;++i)
#define REPR(i,n)    for(ll i=(n)-1;i>=0;--i)
#define REPR1(i,n)   for(ll i=(n);i>0;--i)
#define REPC(i,obj)  for(auto i:obj)
#define ALL(obj)     (obj).begin(),(obj).end()
#define SETP(n)      cout<<fixed<<setprecision(n)
#define VV(T,h,w)    vector<vector<T>>(h,vector<T>(w))
#define VVI(T,h,w,i) vector<vector<T>>(h,vector<T>(w,i))
using namespace std;
using ll = long long;
template<typename T = ll>inline T in() { T ret; cin >> ret; return ret; }

int main()
{
    while (true) {
        ll w = in(), h = in();
        if (w == 0 && h == 0)break;
        auto mp = VVI(ll, h + 2, w + 2, 0);
        REP(i, h) {
            REP(j, w) {
                mp[i + 1][j + 1] = in();
            }
        }
        ll ans = 0;
        REP(i, h) {
            REP(j, w) {
                if (mp[i + 1][j + 1] == 1) {
                    stack<pair<ll, ll>>st; st.emplace(i + 1, j + 1);
                    while (!st.empty()) {
                        auto cood = st.top(); st.pop();
                        mp[cood.first][cood.second] = 2;
                        for (ll dy = -1; dy <= 1; ++dy) {
                            for (ll dx = -1; dx <= 1; ++dx) {
                                ll y = cood.first + dy, x = cood.second + dx;
                                if (mp[y][x] == 1) {
                                    st.emplace(y, x);
                                }
                            }
                        }
                    }
                    ++ans;
                }
            }
        }
        cout << ans << endl;
    }
}

C++: #include <bits/stdc++.h>

using namespace std;

struct posi {
	int x;
	int y;
};

int main() {

	while (1) {
		int w, h;
		cin >> w >> h;

		if (w == 0 && h == 0) { return 0; }
		vector<vector<int>> mapp(h + 2, vector<int>(w + 2));
		for (int i = 1; i <= h; i++) {
			for (int j = 1; j <= w; j++) {
				cin >> mapp[i][j];
			}
		}


		vector<int> dx{ 1,1,0,-1,-1,-1,0,1 };
		vector<int> dy{ 0,1,1,1,0,-1,-1,-1 };

		vector<vector<bool>> seen(h + 2, vector<bool>(w + 2, false));
		deque<posi> todo; //考え方はスタックだけどdequeの方が使い勝手がいい


		posi s; //今いる場所
		int counter = 0;
		for (int i = 1; i <= h; i++) {
			for (int j = 1; j <= w; j++) {
				if (mapp[i][j] == 0) { continue; }
				//seen.resize(h + 2, vector<bool>(w + 2, false));

				if (seen[i][j] == false) {
					counter++;
					seen[i][j] = true;
					todo.push_back({ i,j });

					while (todo.empty() != true) {
						s = todo.back();
						bool tugiflg = false; //次があったらtrue
						for (int k = 0; k < 8; k++) {
							if (seen[s.x + dx[k]][s.y + dy[k]] != true) {
								seen[s.x + dx[k]][s.y + dy[k]] = true;
								if (mapp[s.x + dx[k]][s.y + dy[k]] == 1) {
									todo.push_back({ s.x + dx[k],s.y + dy[k] });;
									tugiflg = true;
									break;
								}
							}
						}
						if (tugiflg == false) {
							todo.pop_back();
						}
					}
				}
			}
		}

		cout << counter << endl;
	}
	return 0;

}