Go: package main

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

const (
	initialBufSize = 100000
	maxBufSize     = 1000000
)

var sc *bufio.Scanner

func initScanner(r io.Reader) *bufio.Scanner {
	buf := make([]byte, initialBufSize)

	sc := bufio.NewScanner(r)
	sc.Buffer(buf, maxBufSize)
	sc.Split(bufio.ScanWords) // bufio.ScanLines
	return sc
}

func main() {
	sc = initScanner(os.Stdin)
	resolve()
}

func resolve() {
	results := []int{}
	for true {
		w, h := scanInt(sc), scanInt(sc)
		if w == 0 && h == 0 {
			break
		}
		grid := make([][]int, h)
		for i := 0; i < h; i++ {
			grid[i] = make([]int, w)
			for j := 0; j < w; j++ {
				grid[i][j] = scanInt(sc)
			}
		}
		num := 0
		for i := range loop0(h) {
			for j := range loop0(w) {
				start := pos{y: i, x: j}
				if grid[start.y][start.x] == 0 {
					continue
				}
				num++
				_dfs(grid, w, h, start)
			}
		}
		results = append(results, num)
	}
	for _, v := range results {
		fmt.Println(v)
	}
	return
}

func _dfs(grid [][]int, w, h int, start pos) {
	grid[start.y][start.x] = 0
	for _, df := range []pos{
		pos{1, 0}, pos{-1, 0},
		pos{0, -1}, pos{0, 1},
		pos{1, 1}, pos{-1, -1},
		pos{-1, 1}, pos{1, -1},
	} {
		np := addPos(start, df)
		if np.y < 0 || h <= np.y || np.x < 0 || w <= np.x {
			continue
		}
		if grid[np.y][np.x] == 0 {
			continue
		}
		_dfs(grid, w, h, np)
	}
}

type pos struct{ x, y int }

func addPos(p, d pos) pos {
	return pos{
		x: p.x + d.x,
		y: p.y + d.y,
	}
}

func loop0(n int) chan int {
	return loop(0, n-1, 1)
}

func loop1(n int) chan int {
	return loop(1, n, 1)
}

func loop(s, e, d int) chan int {
	ch := make(chan int)
	go func() {
		for i := s; i <= e; i += d {
			ch <- i
		}
		close(ch)
	}()
	return ch
}

// snip-scan-funcs
func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	i, _ := strconv.Atoi(sc.Text())
	return int(i)
}
func scanString(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

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

using namespace std;

typedef pair<int, int> p;

int t_x[] = {1, 1, 1, 0, -1, -1, -1, 0};
int t_y[] = {1, 0, -1, -1, -1, 0, 1, 1};

int field[52][52];  

int main()
{
  while (true) {
    memset(field, 0, sizeof field);
    int width, height;
    scanf("%d %d", &width, &height);
    
    if (width == 0 && height == 0) break;
    
    for (int i = 1; i <= height; i++) {
      for (int j = 1; j <= width; j++) {
	scanf(" %d", &field[i][j]);
      }
    }
    
    queue<p> que;
    int c = 0;

    for (int i = 1; i <= height; i++) {
      for (int j = 1; j <= width; j++) {
	if (field[i][j] == 1) {
	  c++;
	  que.push(p(i, j));
	  field[i][j] = 0;
	  while (!que.empty()) {
	    p tmp = que.front();
	    que.pop();
	    //field[tmp.second][tmp.first] = 0;
	    //cout << tmp.first << ", " << tmp.second << endl;
	    for (int k = 0; k < 8; k++) {
	      int tx = tmp.second + t_x[k];
	      int ty = tmp.first + t_y[k];
	      //cout << ty << ", "<< tx << " =  "<< field[ty][tx] << endl;
	      if (field[ty][tx] == 1) {
		field[ty][tx] = 0;
		que.push(p(ty, tx));
	      }
	    }
	    //cout << endl;
	    //cout << i << " " << j << endl;
	    for (int k = 1; k <= height; k++) {
	      for (int l = 1; l <= width; l++) {
		//cout << field[k][l] << " ";
	      }
	      //cout << endl;
	    }
	    //cout << endl;
	  }
	}
      }     
    }
    cout << c << endl;
  }
  return 0;
}

C++: #include <cstdio>

int w, h;
int c[50][50];

void dfs(int a, int b){
	for(int i = 0; i < 3; i++){
		for(int j = 0; j < 3; j++){
			int A = a+i-1, B = b+j-1;
			if(0<=A&&A<w&&0<=B&&B<h&&c[A][B]){
				c[A][B] = 0;
				dfs(A,B);
			}
		}
	}
}

int main(){
	while(scanf("%d%d", &w, &h),w||h){
		int ans = 0;
		for(int i = 0; i < h; i++){
			for(int j = 0; j < w; j++){
				scanf("%d", &c[j][i]);
			}
		}
		for(int i = 0; i < w; i++){
			for(int j = 0; j < h; j++){
				if(c[i][j]){
					c[i][j] = 0;
					ans++;
					dfs(i,j);
				}
			}
		}
		printf("%d\n", ans);
	}
}

C++: /*
URL: http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=1160&lang=jp
?????????: How Many Islands?
?????°:
18:49 ?????????????????????????§£?????????
*/
#include <iostream>
using namespace std;

int dat[52][52]; // ??¨?????????1???????????£?????°

void delete_island_from(int i, int j)
{
	int dx[8] = {-1,-1,-1, 0,  0, 1, 1, 1};
	int dy[8] = {-1, 0, 1,-1,  1,-1, 0, 1};

	dat[i][j] = 0;
	for(int k=0;k<8;k++) {
		if(dat[i+dx[k]][j+dy[k]]) {
			delete_island_from(i+dx[k],j+dy[k]);
		}
	}
}


int main()
{
	while(true){ // data set
		//dat???0????????¢
		for(int i=0;i<52;i++){
			for(int j=0;j<52;j++){
				dat[i][j]=0;
			}
		}

		int w; int h;
		cin >> w >> h;
		if(w == 0 && h == 0) {break;}

		for(int i=0; i<h;i++) {
			for(int j=0;j<w;j++) {
				cin >> dat[i+1][j+1]; // ??¨?????????1???????????£?????°
			}
		}

		int ans = 0;
		while(true) {
			for(int i=0; i<h+2;i++) { // ????????£?????°??????
				for(int j=0;j<w+2;j++) {
					if(dat[i][j] == 1){
						delete_island_from(i,j);
						ans++;
						goto label1;
					}
				}
			} // all is ocean
			cout << ans << endl;
			break;


			label1: ;
		}
	}
}

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;
}