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>
#define rep(i, n) for (int i = 0; i < (n); i++)
using namespace std;
#define WHITE 0
#define GRAY 1
typedef long long LL;
const int MAXN = 60;
int w,h,ans, mapp[MAXN][MAXN], color[MAXN][MAXN];
vector<int> v_ans;

void dfs_visit(int u,int k) {

	color[u][k] = GRAY;//参照したことを示す


	if(mapp[u][k + 1] == 1 && color[u][k + 1] == WHITE) {//右
		dfs_visit(u,k + 1);
	}

	if(mapp[u + 1][k + 1] == 1 && color[u + 1][k + 1] == WHITE) {//右下
		dfs_visit(u + 1,k + 1);
	}

	if(mapp[u + 1][k] == 1 && color[u + 1][k] == WHITE) {//下
		dfs_visit(u + 1,k);
	}

    if(k > 0){
        if(mapp[u + 1][k - 1] == 1 && color[u + 1][k - 1] == WHITE) {// 左下
            dfs_visit(u + 1,k - 1);
        }
    }

    if(k > 0){
        if(mapp[u][k - 1] == 1 && color[u][k - 1] == WHITE) {// 左
            dfs_visit(u,k - 1);
        }
    }

    if(u > 0){
        if(mapp[u - 1][k] == 1 && color[u - 1][k] == WHITE) {// 上
            dfs_visit(u - 1,k);
        }
    }

    if(u > 0){
        if(mapp[u - 1][k + 1] == 1 && color[u - 1][k + 1] == WHITE) {// 右上
            dfs_visit(u - 1,k + 1);
        }
    }

    if(u > 0 && k > 0){
        if(mapp[u - 1][k - 1] == 1 && color[u - 1][k - 1] == WHITE) {// 左上
            dfs_visit(u - 1,k - 1);
        }
    }


}

void dfs() {
    int ans = 0;
	for(int i = 0; i < h; i++) {
        for(int j = 0; j < w; j++){
            if(mapp[i][j] == 1 && color[i][j] == WHITE ) {//未探訪の島なら探索

                dfs_visit(i,j);
                ans += 1;
            }
        }

	}

	v_ans.push_back(ans);

}

int main() {

    while(1){
        memset(mapp, 0, sizeof(mapp));//木情報をリセット
        memset(color, 0, sizeof(color));//探訪情報をリセット
        cin >> w >> h;
        if(w == 0) break;
        for(int i = 0; i < h; i++){

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

        }
        dfs();
    }
    rep(i,v_ans.size()) cout <<v_ans[i] <<endl;
	return 0;
}