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;

int main() {
    while (true) {
        bool seen[100][100] = {false};
        vector<vector<int>> field;
        stack<pair<int, int>> to_visit;
        int cnt = 0;

        int w, h;
        cin >> w >> h;

        if (w == 0 || h == 0) {
            break;
        }

        field.assign(h, vector<int>(w, 0));
        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) {
                cin >> field[i][j];
            }
        }

        // for (int i = 0; i < h; i++) {
        //     for (int j = 0; j < w; j++) {
        //         if (field[i][j] == 0) {
        //             cout << "^";
        //         }
        //         else {
        //             cout << "O";
        //         }
        //     }
        //     cout << endl;
        // }

        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) {
                if (field[i][j] == 0) {
                    continue;
                }
                if (seen[i][j] == true) {
                    continue;
                }

                cnt++;
                to_visit.push(make_pair(i, j));
                seen[i][j] = true;
                while (to_visit.empty() == false) {
                    pair<int, int> cur_pos = to_visit.top(); to_visit.pop();
                    int cur_h = cur_pos.first;
                    int cur_w = cur_pos.second;
                    for (int dh = -1; dh <= 1; dh++) {
                        for (int dw = -1; dw <= 1; dw++) {
                            if (dh == 0 && dw == 0) {
                                continue;
                            }

                            int next_h = cur_h + dh;
                            int next_w = cur_w + dw;
                            if (next_h < 0 || next_h >= h || next_w < 0 || next_w >= w) {
                                continue;
                            }
                            if (seen[next_h][next_w] == true) {
                                continue;
                            }
                            if (field[next_h][next_w] == 0) {
                                continue;
                            }
                            to_visit.push(make_pair(next_h, next_w));
                            seen[next_h][next_w] = true;
                        }
                    }
                }
            }
        }

        cout << cnt << endl;
    }

    return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <cstdlib>

using namespace std;

#define MAX_L 50

int graph[MAX_L+2][MAX_L+2];

void search(int x, int y, int num){
	graph[x][y]=num;
	for(int i=-1; i<=1; i++){
	    for(int j=-1; j<=1; j++){
	      if(graph[x+i][y+j] == 1){search(x+i, y+j, num);}
	    }
	}
}

int main()
{
	int w, h, label;
 
	while(true){
		scanf("%d%d\n",&w, &h);
		if(w==0 && h==0){return 0;}

		for(int i=0; i<h+2; i++){
			for(int j=0; j<w+2; j++){
				graph[i][j]=0;
			}
		}

		for(int i=1; i<h+1; i++){
			for(int j=1; j<w+1; j++){
				cin >> graph[i][j];
			}
		}

		label = 1;
		for(int i=1; i<h+1; i++){
			for(int j=1; j<w+1; j++){
				if(graph[i][j]==1){
					label++;
					search(i,j,label);
				}
			}
		}
		cout << label-1 << endl;		
	}	
}