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;
#define rep(i, n) for (int i = 0; i < n; i++)
#define ll long long int
#define INF 1000000007
#define llINF 1000000000000000007
#define v(i) vector<i>
#define vv(i) vector<vector<i>>
// cin.eof() 入力個数の問題
// int num = atoi(string.c_str()); 文字列の整数変換
bool visited[51][51];
int h, w;
int A[] = {1, 1, 1, 0, 0, -1, -1, -1};
int B[] = {0, 1, -1, 1, -1, 0, 1, -1};
void dfs(int x, int y, vv(int) & c) {
    if (x < 0 || x >= h || y < 0 || y >= w || c[x][y] == 0)
        return;
    if (visited[x][y])
        return;
    visited[x][y] = true;
    //cout<<"(x,y)=="<<x<<","<<y<<endl;
    rep(i, 8) {
        dfs(x + A[i], y + B[i], c);
    }
}

int main() {
   while (1) {
        cin >> w >> h;
        if(w==0 && h==0) return 0;
        vv(int) c;
        rep(i, h) {
            c.push_back({});
            rep(j, w) {
                int a;
                cin >> a;
                c[i].push_back(a);
            }
        }
        rep(i, 51) {
            rep(j, 51) {
                visited[i][j] = false;
            }
        }
        int ans = 0;
        rep(i, h) {
            rep(j, w) {
                if (visited[i][j] || c[i][j] == 0)
                    continue;
                dfs(i, j, c);
                //cout<<"dfs"<<endl;
                ans++;
            }
        }
        cout << ans << endl;
    }
    return 0;
}

C++: #include <iostream>
#include <vector>
#include <stack>

void dfs(std::vector<std::vector<int> > &map, std::stack<std::pair<int, int> > &st, int &number) {
    int dy[8] = {-1, -1, -1, 0, 0, 1, 1, 1};
    int dx[8] = {-1, 0, 1, -1, 1, -1, 0, 1};
    std::pair<int, int>  coord;
    coord.first = st.top().first;
    coord.second = st.top().second;
    map[coord.first][coord.second] = 0;
    st.pop();
    for (int i = 0; i < 8; i++) {
        if (map[coord.first + dy[i]][coord.second + dx[i]] == 1) {
            st.push(std::make_pair(coord.first + dy[i], coord.second + dx[i]));
            dfs(map, st, number);
        }
    }
    return;
}

int main(void) {
    int w;
    int h;
    int number;
    while (std::cin >> w >> h) {
        if (w == 0 && h == 0) {
            break;
        }
        std::stack<std::pair<int, int> > st;
        number = 0;
        std::vector<std::vector<int> > map(h + 2, std::vector<int>(w + 2, 0));
        for (int i = 1; i <= h; i++) {
            for (int j = 1; j <= w; j++) {
                std::cin >> map[i][j];
            }
        }
        for (int i = 1; i <= h; i++) {
            for (int j = 1; j <= w; j++) {
                if (map[i][j] == 1) {
                    st.push(std::make_pair(i, j));
                    map[i][j] = 0;
                    dfs(map, st, number);
                    number++;
                }
            }
        }
        std::cout << number << std::endl;
    }
    return 0;
}

C++: #include <iostream>
#include <vector>
using namespace std;
int w, h;
vector<int> ans;
char c[55][55];

void dfs(int x, int y) {
    c[x][y] = '0';
    for (int dh = -1; dh <= 1; dh++) {
        for (int dw = -1; dw <= 1; dw++) {
            int nh = x + dh, nw = y + dw;
            if (0 <= nh && 0 <= nw && nh < h && nw < w && c[nh][nw] == '1') dfs(nh, nw);
        }
    }
    return;
}

int main() {
    while (1) {
        cin >> w >> h;
        if (w == 0 && h == 0) break;
        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) cin >> c[i][j];
        }
        int cnt = 0;
        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) {
                if (c[i][j] == '1') { 
                    dfs(i, j);
                    cnt++;
                }
            }
        }
        ans.push_back(cnt);
    }
    for (int i = 0; i < ans.size(); i++) {
        cout << ans[i] << endl;
    }
}