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>

void explore(const int i, const int j, const int w, const int h, const std::array<std::array<int, 50>, 50>& state, std::array<std::array<bool, 50>, 50>& visited)
{
    for (int a = -1; a < 2; a++) {
        for (int b = -1; b < 2; b++) {
            if (0 <= i + a && i + a < h && 0 <= j + b && j + b < w && (a != 0 || b != 0) && !visited.at(i + a).at(j + b) && state.at(i + a).at(j + b) == 1) {
                visited.at(i + a).at(j + b) = true;
                explore(i + a, j + b, w, h, state, visited);
            }
        }
    }
}

int main()
{
    while (true) {
        int w, h;
        std::cin >> w >> h;
        if (w == 0 && h == 0) {
            break;
        }
        int max_land_id = 0;
        std::array<std::array<int, 50>, 50> state;
        std::array<std::array<bool, 50>, 50> visited;
        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) {
                std::cin >> state.at(i).at(j);
                visited.at(i).at(j) = false;
            }
        }
        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) {
                if (state.at(i).at(j) == 1 && !visited.at(i).at(j)) {
                    visited.at(i).at(j) = true;
                    explore(i, j, w, h, state, visited);
                    ++max_land_id;
                }
            }
        }
        std::cout << max_land_id << std::endl;
    }
    return 0;
}

C++: #include <iostream>
using namespace std;
int a[52][52];
int sima(int i,int j,int k){
	if(a[i-1][j-1] == 1){
		a[i-1][j-1] = k;
		sima(i-1,j-1,k);
	}
	if(a[i-1][j] == 1){
		a[i-1][j] = k;
		sima(i-1,j,k);
	}
	if(a[i-1][j+1] == 1){
		a[i-1][j+1] = k;
		sima(i-1,j+1,k);
	}
	if(a[i][j-1] == 1){
		a[i][j-1] = k;
		sima(i,j-1,k);
	}
	if(a[i][j+1] == 1){
		a[i][j+1] = k;
		sima(i,j+1,k);
	}
	if(a[i+1][j-1] == 1){
		a[i+1][j-1] = k;
		sima(i+1,j-1,k);
	}
	if(a[i+1][j] == 1){
		a[i+1][j] = k;
		sima(i+1,j,k);
	}
	if(a[i+1][j+1] == 1){
		a[i+1][j+1] = k;
		sima(i+1,j+1,k);
	}
}

int main() {
	int w,h,k;
	while(1){
		for(int i = 0;i < 52;i++){
			for(int j = 0;j < 52;j++){
				a[i][j] = 0;
			}
		}
		cin >> w >> h;
		if(w == 0)break;
		for(int i = 1;i <= h;i++){
			for(int j = 1;j <= w;j++){
				cin >> a[i][j];
			}
		}
		k = 2;
		for(int i = 1;i <= h;i++){
			for(int j = 1;j <= w;j++){
				if(a[i][j] == 1){
					sima(i,j,k);
					k++;
				}
			}
		}
		cout << k-2 <<endl;
	}
	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
int dx[]={-1,0,1,-1,1,-1,0,1};
int dy[]={-1,-1,-1,0,0,1,1,1};

    int w,h;
void dfs(int i,int j,vector<vector<int>>& x){
        x[i][j]=0;
        for(int r=0;r<8;r++)
            if(0<=i+dx[r] && i+dx[r]<h && 0<=j+dy[r] && j+dy[r]<w && x[i+dx[r]][j+dy[r]])
                dfs(i+dx[r],j+dy[r],x);



}
int main(){
    while(cin>>w>>h,w){
        vector<vector<int>> x(h,vector<int>(w,0));
        for(int i=0;i<h;i++)
            for(int j=0;j<w;j++)
                cin>>x[i][j];
        int cnt=0;
        for(int i=0;i<h;i++)
            for(int j=0;j<w;j++){
                if(x[i][j]){
                    cnt++;
                    dfs(i,j,x);


                }




            }
        cout<<cnt<<endl;



    }


    return 0;
}

C++: #include <stack>
#include <cstdio>

using namespace std;
bool c[52][52]; 
int check(int arg[][52], int i, int j);

int main(void){
	int w, h;
	int arg[52][52];
	int i, j;
	int count;


	scanf("%d %d", &w, &h);
	while(w!=0 && h!=0){
		count=0;
		for(i=0; i<=h+1; i++){
			for(j=0; j<=w+1; j++){
				if(i==0 || i==(h+1) || j==0 || j==(w+1)){
					c[i][j]=false; 
					arg[i][j]=0;
				}
			}
		}

		for(i=1; i<=h; i++){
			for(j=1; j<=w; j++){ 
				scanf("%d",&arg[i][j]);
				if(arg[i][j])
					c[i][j]=true;
				else
					c[i][j]=false;
			}
		}

		for(i=1; i<=h; i++){
			for(j=1; j<=w; j++){
				if(arg[i][j]==1 && c[i][j]==true){
					count = count + check(arg, i, j);
				}
			}
		}

		printf("%d\n", count);
		scanf("%d %d", &w, &h);
	}

	return 0;
}

int check(int arg[][52], int i, int j){

	if(arg[i+1][j]==1 && c[i+1][j]==true){
		c[i+1][j]=false;
		check(arg, i+1, j);
	}
	if(arg[i][j+1]==1 && c[i][j+1]==true){
		c[i][j+1]=false;
		check(arg, i, j+1);
	}
	if(arg[i-1][j]==1 && c[i-1][j]==true){
		c[i-1][j]=false;
		check(arg, i-1, j);
	}
	if(arg[i][j-1]==1 && c[i][j-1]==true){
		c[i][j-1]=false;
		check(arg, i, j-1);
	}
	if(arg[i-1][j+1]==1 && c[i-1][j+1]==true){
		c[i-1][j+1]=false;
		check(arg, i-1, j+1);
	}
	if(arg[i-1][j-1]==1 && c[i-1][j-1]==true){
		c[i-1][j-1]=false;
		check(arg, i-1, j-1);
	}
	if(arg[i+1][j+1]==1 && c[i+1][j+1]==true){
		c[i+1][j+1]=false;
		check(arg, i+1, j+1);
	}
	if(arg[i+1][j-1]==1 && c[i+1][j-1]==true){
		c[i+1][j-1]=false;
		check(arg, i+1, j-1);
	}

	return 1;

}