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<iostream>
#include<cmath>
#include<algorithm>

using namespace std;

int w,h;
bool grid[50][50];

void rec(int x,int y){
  grid[y][x]=false;
  for(int i=-1;i<2;i++){
    for(int j=-1;j<2;j++){
      int ny=y+i,nx=x+j;
      if(0<=nx && nx<w && 0<=ny && ny<h)
	if(grid[ny][nx])rec(nx,ny);
    }
  }
}

int main(void){

  while(cin >> w >> h,w|h){
    for(int i=0;i<h;i++){
      for(int j=0;j<w;j++){
	cin >> grid[i][j];
      }
    }
    
    int ans=0;
    for(int i=0;i<h;i++){
      for(int j=0;j<w;j++){
	if(grid[i][j])rec(j,i),ans++;
      }
    }
    cout << ans << endl;
  }

  return 0;
}

C++: //#define _GRIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;

#define int long long

int dx[]{1, 0, -1, 0, 1, -1, 1, -1};
int dy[]{0, 1, 0, -1, 1, -1, -1, 1};

signed main()
{
    int w, h;
    while(cin>>w>>h, w) {
        int field[h+1][w+1];
        for(int i=0; i<h; ++i) {
            for(int j=0; j<w; ++j) {
                int c;
                cin >> c;
                field[i][j] = c;
            }
        }

        int ans = 0;
        for(int i=0; i<h; ++i) {
            for(int j=0; j<w; ++j) {
                if(field[i][j]==1) {
                    ans++;
                    queue<pair<int, int> > q;
                    q.push(make_pair(i, j));
                    while(!q.empty()) {
                        pair<int, int> p = q.front();
                        q.pop();
                        int x = p.first;
                        int y = p.second;
                        field[x][y] = 0;
                        for(int k=0; k<8; ++k) {
                            int nx = x + dx[k];
                            int ny = y + dy[k];
                            if(nx>=0&&nx<h&&ny>=0&&ny<w&&field[nx][ny]==1) {
                                q.push(make_pair(nx, ny));
                            }
                        }
                    }
                }
            }
        }

        cout << ans << endl;
    }
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define ll long long
#define rep(i,b) for(ll i=0;i<b;i++)

using namespace std;

int field[50][50];
int N,M;
void dfs(int x,int y){
    field[x][y]=0;
    for(int dx=-1;dx<=1;dx++){
        for(int dy=-1;dy<=1;dy++){
            int nx=x+dx,ny=y+dy;
            if(0<=nx&&nx<N&&0<=ny&&ny<M&&field[nx][ny]==1)dfs(nx,ny);
        }
    }
}
int main(){
    for(;;) {
        cin>>M>>N;
        if(N==0)break;
        rep(i,N){
            rep(j,M){
                cin>>field[i][j];
            }
        }
        int res = 0;
        for (int i = 0; i < N; i++) {
            for (int j = 0; j < M; j++) {
                if (field[i][j] == 1) {
                    dfs(i, j);
                    res++;
                }
            }
        }
        cout << res << endl;
    }
}

C++: #include<iostream>
using namespace std;
int Island[52][52];
void solve(int y,int x) {
	Island[y][x] = 0;
	for (int i = -1; i <= 1; ++i) {
		for (int j = -1; j <= 1; ++j) {
			if (Island[y + i][x + j]) solve(y + i, x + j);
		}
	}
}
int main() {
	int w,h;
	while (cin >> w >> h&&w&&h) {
		int cnt = 0;
		for (int i = 0; i < h + 2; ++i) {
			for (int j = 0; j < w + 2; ++j) {
				if (i == 0 || j == 0 || i == h + 1 || j == w + 1) Island[i][j] = 0;
				else cin >> Island[i][j];
			}
		}
		for (int i = 1; i < h + 1; ++i) {
			for (int j = 1; j < w + 1; ++j) {
				if (Island[i][j]) {
					solve(i, j);
					++cnt;
				}
			}
		}
		cout << cnt << endl;
	}
	return 0;
}