Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

var sc = bufio.NewScanner(os.Stdin)
var route [][]int

func scanInt() int {
	num, _ := strconv.Atoi(scanString())
	return num
}

func scanString() string {
	sc.Scan()
	return sc.Text()
}

func init() {
	sc.Split(bufio.ScanWords)
}

func dfs(h, w int) {
	if route[h][w] == 0 {
		return
	}

	route[h][w] = 0
	for _, x := range []int{-1, 0, 1} {
		for _, y := range []int{-1, 0, 1} {
			if route[h+x][w+y] == 0 {
				continue
			}
			dfs(h+x, w+y)
		}
	}
}

func main() {
	writer := bufio.NewWriter(os.Stdout)
	for {
		w, h := scanInt(), scanInt()
		if w == 0 && h == 0 {
			break
		}

		route = make([][]int, h+2)
		route[0] = make([]int, w+2)
		for i := 1; i <= h; i++ {
			route[i] = make([]int, w+2)
			for j := 1; j <= w; j++ {
				route[i][j] = scanInt()
			}
		}
		route[h+1] = make([]int, w+2)

		total := 0
		for i := 1; i <= h; i++ {
			for j := 1; j <= w; j++ {
				if route[i][j] == 1 {
					total++
					dfs(i, j)
				}
			}
		}
		fmt.Fprintln(writer, total)
	}
	writer.Flush()
}

C++: #include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <queue>
using namespace std;

struct Point {
	int x,y;
};

bool map[50][50];
const int dx[8] = {1,1,0,-1,-1,-1,0,1};
const int dy[8] = {0,1,1,1,0,-1,-1,-1};
int w,h;

void bfs(int x,int y) {

	queue<Point> q;
	Point p,p2;
	p.x = x;
	p.y = y;

	q.push(p);
	map[p.x][p.y] = false;
	while(!q.empty()) {
		p = q.front();
		q.pop();

		for(int i = 0;i < 8;i++) {
			p2.x = p.x + dx[i];
			p2.y = p.y + dy[i];

			if(p2.x < 0 || p2.x >= w) continue;
			if(p2.y < 0 || p2.y >= h) continue;

			if(map[p2.x][p2.y]) {
				q.push(p2);
				map[p2.x][p2.y] = false;
			}
		}
	}
}

int main() {

	while(cin >> w >> h && !(w == 0 && h == 0)) {
		for(int y = 0;y < h;y++) {
			for(int x = 0;x < w;x++) cin >> map[x][y];
		}
		int ct = 0;
		for(int y = 0;y < h;y++) {
			for(int x = 0;x < w;x++) {
				if(map[x][y]) {
					ct++;
					bfs(x,y);
				}
			}
		}
		cout << ct << endl;
	}

}

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

using namespace std;

void solve(vector<vector<int> >& C, int cur_x, int cur_y) {
  C[cur_y][cur_x] = 0;
  for (int i = -1; i < 2; ++i) {
    for (int j = -1; j < 2; ++j) {
      int next_x = cur_x + j;
      int next_y = cur_y + i;
      if (next_x >= 0 && next_x < C[0].size() && next_y >= 0 && next_y < C.size()) {
        if (C[next_y][next_x] == 1)
          solve(C, next_x, next_y);
      }
    }
  }
}


int main(int argc, char* argv[]) {
  vector<int> rets;
  while (true) {
    int w, h;
    cin >> w >> h;

    if (w == 0 && h == 0)
      break;

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

    int ret = 0;
    for (int i = 0; i < h; ++i) {
      for (int j = 0; j < w; ++j) {
        if (C[i][j] == 1) {
          ++ret;
          solve(C, j, i);
        }
      }
    }

    rets.push_back(ret);
  }

  for (int i = 0; i < rets.size(); ++i)
    cout << rets[i] << endl;

  return 0;
}

C++: #include <bits/stdc++.h>
#define debug(x) cerr << #x << ": " << x << '\n';
using namespace std;
using ll = long long;
using P = pair<int, int>;
const int INF = (int)1e9;

int w, h;
int c[51][51];
int dx[] = {1, -1, 0, 0, 1, 1, -1, -1};
int dy[] = {0, 0, 1, -1, 1, -1, 1, -1};

void dfs(int y, int x){
	c[y][x] = 0;
	for(int i = 0; i < 8; i++){
		int ny = y + dy[i], nx = x + dx[i];
		if(0<=ny and ny<h and 0<=nx and nx<w and c[ny][nx]==1){
			dfs(ny, nx);
		}
	}
}

int solve(){
	int res = 0;
	for(int i = 0; i < h; i++){
		for(int j = 0; j < w; j++){
			if(c[i][j] == 1){
				dfs(i, j);
				res++;
			}
		}
	}

	return res;
}

int main(void){
	while(scanf("%d%d", &w, &h) != EOF){
		if(w == 0 and h == 0) break;
		for(int i = 0; i < h; i++){
			for(int j = 0; j < w; j++){
				scanf("%d", &(c[i][j]));
			}
		}
		printf("%d\n", solve());
	}

	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int mod = 1e9 + 7;
const int inf = (1 << 30) - 1;
const ll infll = (1LL << 61) - 1;
#define fast() ios::sync_with_stdio(false), cin.tie(0), cout.tie(0)
#define digit(N) cout << fixed << setprecision((N))

int H, W;
int dx[] = {1, 0, -1, 0, 1, 1, -1, -1};
int dy[] = {0, 1, 0, -1, 1, -1, 1, -1};
int grid[50][50], visited[50][50];

int main()
{
    while (cin >> W >> H)
    {
        if (H == 0 && W == 0)
            return 0;

        for (int i = 0; i < H; i++)
        {
            for (int j = 0; j < W; j++)
            {
                cin >> grid[i][j];
                visited[i][j] = 0;
            }
        }

        int ans = 0, cnt = 0;
        queue<pair<int, int>> que;
        for (int i = 0; i < H; i++)
        {
            for (int j = 0; j < W; j++)
            {
                if (grid[i][j] == 1 && visited[i][j] == 0)
                {
                    que.push({i, j});

                    while (!que.empty())
                    {
                        auto p = que.front();
                        que.pop();
                        visited[p.first][p.second] = 1;
                        for (int k = 0; k < 8; k++)
                        {
                            int nx = p.first + dx[k], ny = p.second + dy[k];
                            if (nx < 0 || nx >= H)
                                continue;
                            if (ny < 0 || ny >= W)
                                continue;
                            if (visited[nx][ny])
                                continue;

                            visited[nx][ny] = 1;
                            if (grid[nx][ny] == 1)
                                que.push({nx, ny});
                        }
                    }
                    ans++;
                }
            }
        }

        cout << ans << endl;
    }
}

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

using namespace std;
using ll = long long;
using Graph = vector<vector<int>>;
using pint = pair<int, int>;
int dx[8] = {1, 0, -1, 0, 1, -1, 1, -1};
int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};
const int MOD = 1000000009;
const long long INF = 1LL << 60;

void dfs(Graph& G, int y, int x) {
    int H = G.size();
    int W = G[0].size();
    G[y][x] = -1;
    for (int i = 0; i < 8; ++i) {
        int ny = y + dy[i];
        int nx = x + dx[i];
        if (ny < 0 || ny >= H || nx < 0 || nx >= W) continue;
        if (G[ny][nx] != 1) continue;
        dfs(G, ny, nx);
    }
}

int main() {
    while(1) {
        int W, H;
        cin >> W >> H;
        if (W == 0 && H == 0) break;
        Graph C(H, vector<int>(W, 0));
        for (int i = 0; i < H; ++i) {
            for (int j = 0; j < W; ++j) cin >> C[i][j];
        }
        int res = 0;
        for (int i = 0; i < H; ++i) {
            for (int j = 0; j < W; ++j) {
                if (C[i][j] == 1) {
                    ++res;
                    dfs(C, i, j);
                }
            }
        }
        cout << res << endl;
    }
    return 0;
}

C++: #include <iostream>
#include <vector>
#include <string>
#include <queue>
#include <climits>
#include <utility>

using namespace std;

int dfs( vector< vector<int> > &board, const int &h, const int &w, int y, int x )
{
	if ( !( 0 <= y && y < h && 0 <= x && x < w ) || 
		board[y][x] == 0 )
	{
		return 0;
	}

	board[y][x] = 0;

	for ( int i = -1; i <= 1; i++ )
	{
		for ( int j = -1; j <= 1; j++ )
		{
			dfs( board, h, w, y + i, x + j );
		}
	}
	return 1;
}

int main()
{
	while ( true )
	{
		int w, h;
		cin >> w >> h;

		if ( !( w | h ) )
		{
			break;
		}

		vector< vector<int> > board( h, vector<int>( w ) );

		for ( int i = 0; i < h; i++ )
		{
			for ( int j = 0; j < w; j++ )
			{
				cin >> board[i][j];
			}
		}

		int res = 0;

		for ( int i = 0; i < h; i++ )
		{
			for ( int j = 0; j < w; j++ )
			{
				res += dfs( board, h, w, i, j );
			}
		}

		cout << res << endl;
	}

	return 0;
}