Go: // AOJ 1160: How Many Islands? http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=1160

package main

import (
	"bufio"
	"container/list"
	"fmt"
	"os"
	"strconv"
)

var SEA = 0
var LAND = 1

func nextInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

func discoverIslands(M, V [][]int, H, W int) int {
	// 島を探す
	queue := list.New()
	islands := 0
	for i := 1; i <= H; i++ {
		for j := 1; j <= W; j++ {
			// 訪問済みの土地ならスキップ
			if V[i][j] == 1 {
				continue
			}

			// 訪問中の土地が海なら訪問済みにしてスキップ
			if M[i][j] == SEA {
				V[i][j] = 1
				continue
			}

			// 未訪問の陸地が見つかったので
			// 島の数を1つ増やし、この陸地から辿れる陸地を訪問していく
			islands++
			queue.PushBack([]int{i, j})

			for queue.Len() > 0 {
				cur := queue.Remove(queue.Front()).([]int)
				h, w := cur[0], cur[1]
				if V[h][w] == 1 {
					continue
				}
				V[h][w] = 1

				// 全方向に未訪問の陸地がないか探索
				for v := -1; v <= 1; v++ {
					for l := -1; l <= 1; l++ {
						dh := h + v
						dw := w + l
						if M[dh][dw] == LAND && V[dh][dw] == 0 {
							queue.PushBack([]int{dh, dw})
						}
					}
				}
				/*
					if M[h-1][w] == LAND {
						queue.PushBack([]int{h - 1, w})
					}
					if M[h-1][w+1] == LAND {
						queue.PushBack([]int{h - 1, w + 1})
					}
					if M[h][w+1] == LAND {
						queue.PushBack([]int{h, w + 1})
					}
					if M[h+1][w+1] == LAND {
						queue.PushBack([]int{h + 1, w + 1})
					}
					if M[h+1][w] == LAND {
						queue.PushBack([]int{h + 1, w})
					}
					if M[h+1][w-1] == LAND {
						queue.PushBack([]int{h + 1, w - 1})
					}
					if M[h][w-1] == LAND {
						queue.PushBack([]int{h, w - 1})
					}
					if M[h-1][w-1] == LAND {
						queue.PushBack([]int{h - 1, w - 1})
					}
				*/
			}
		}
	}
	return islands
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	for {
		W, H := nextInt(sc), nextInt(sc)

		if W == 0 && H == 0 {
			break
		}
		// Initialize map and visted list
		M := make([][]int, H+2)
		V := make([][]int, H+2)
		for i := 0; i < H+2; i++ {
			M[i] = make([]int, W+2)
			V[i] = make([]int, W+2)
		}
		for i := 1; i <= H; i++ {
			for j := 1; j <= W; j++ {
				M[i][j] = nextInt(sc)
			}
		}

		islands := discoverIslands(M, V, H, W)

		fmt.Println(islands)
	}
}

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rrep(i, n) for (int i = (int)(n - 1); i >= 0; i--)
#define all(x) (x).begin(), (x).end()
#define sz(x) int(x.size())
#define get_unique(x) x.erase(unique(all(x)), x.end());
typedef long long ll;
typedef complex<double> Complex;
const int INF = 1e9;
const ll MOD = 1e9 + 7;
const ll LINF = 1e18;
template <class T>
bool chmax(T& a, const T& b) {
    if (a < b) {
        a = b;
        return 1;
    }
    return 0;
}
template <class T>
bool chmin(T& a, const T& b) {
    if (b < a) {
        a = b;
        return 1;
    }
    return 0;
}
template <class T>
vector<T> make_vec(size_t a) {
    return vector<T>(a);
}
template <class T, class... Ts>
auto make_vec(size_t a, Ts... ts) {
    return vector<decltype(make_vec<T>(ts...))>(a, make_vec<T>(ts...));
}

int main() {
    while (1) {
        int w, h;
        cin >> w >> h;
        if (w == 0 && h == 0) break;
        auto v = make_vec<int>(h, w);
        rep(i, h) rep(j, w) cin >> v[i][j];
        int cnt = 0;
        auto used = make_vec<bool>(h, w);
        rep(i, h) rep(j, w) {
            if (!used[i][j] && v[i][j] == 1) {
                queue<pair<int, int>> q;
                q.push(make_pair(i, j));
                while (sz(q)) {
                    int y, x;
                    tie(y, x) = q.front();
                    q.pop();
                    for (int dy = -1; dy <= 1; dy++) {
                        for (int dx = -1; dx <= 1; dx++) {
                            if (dy == 0 && dx == 0) continue;
                            int ny = y + dy;
                            int nx = x + dx;
                            if (!(0 <= ny && ny < h && 0 <= nx && nx < w))
                                continue;
                            if (v[ny][nx] == 0 || used[ny][nx]) continue;
                            q.push(make_pair(ny, nx));
                            used[ny][nx] = 1;
                        }
                    }
                }
                cnt++;
            }
        }
        cout << cnt << endl;
    }
}

C++: #include<iostream>
using namespace std;
int map[114][514];
void dfs(int i, int j) {
	map[i][j] = 0;
	for (int a = -1; a < 2; a++) {
		for (int b = -1; b < 2; b++) {
			if (map[i + a][b + j] == 1)dfs(i + a, b + j);
		}
	}
	return;
}
int main() {
	int h, w; 
	while (cin >> h >> w, h, w) {
		for (int i = 1; i <= w; i++) {
			for (int j = 1; j <= h; j++) {
				cin >> map[i][j];
			}
		}
		int ans = 0;
		for (int i = 1; i <= w; i++) {
			for (int j = 1; j <= h; j++) {
				if (map[i][j]) {
					dfs(i, j);
					ans++;
				}
			}
		}
		cout << ans << endl;
	}
}

C++: #include<iostream>
#include<vector>
#include <unordered_map>
#include <algorithm>
#include <functional>
#include <map>
#include <string>
#include <sstream>
#include <cmath>
#include <float.h>
using namespace std;



bool checked[50][50];
int island[50][50];
int count1 = 0;
int w, h;
vector<int> num;
unsigned long long int mod = 1000000007;

void checkIsland(int x, int y) {
    if (x < 0 || x >= h || y >= w || y < 0) { return; }
    if (!island[x][y] || checked[x][y]) {
        checked[x][y] = true;
        return;
    }
    checked[x][y] = true;
    checkIsland(x + 1, y);
    checkIsland(x + 1, y + 1);
    checkIsland(x + 1, y - 1);
    checkIsland(x, y + 1);
}

void runtime() {
    count1 = 0;
    for (int i = 0; i < h; ++i) {
        for (int j = 0; j < w; ++j) {
            checked[i][j] = false;
            cin >> island[i][j];
        }
    }
    for (int i = 0; i < h; ++i) {
        for (int j = 0; j < w; ++j) {
            if (checked[i][j]) continue;
            if (island[i][j]) {
                count1++;
                checkIsland(i, j);
            }
            else {
                checked[i][j] = true;
            }
        }
    }
    num.push_back(count1);
}


int main() {
    cin >> w >> h;
    while (!(w == 0 && h == 0)) {
        runtime();
        cin >> w >> h;
    }
    for (auto i : num) {
        cout << i << endl;
    }
    return 0;
}