Go: package main

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

var (
	readString func() string
	readBytes  func() []byte
	stdout     *bufio.Writer
)

func init() {
	readString, readBytes = newReadString(os.Stdin)
	stdout = bufio.NewWriter(os.Stdout)
}

func newReadString(ior io.Reader) (func() string, func() []byte) {
	r := bufio.NewScanner(ior)
	r.Buffer(make([]byte, 1024), math.MaxInt32)
	r.Split(bufio.ScanWords)

	f1 := func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
	f2 := func() []byte {
		return []byte(f1())
	}
	return f1, f2
}

func readInt() int {
	return int(readInt64())
}

func readInt64() int64 {
	i, err := strconv.ParseInt(readString(), 10, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

func readFloat64() float64 {
	f, err := strconv.ParseFloat(readString(), 64)
	if err != nil {
		panic(err.Error())
	}
	return f
}

func printf(f string, args ...interface{}) (int, error) {
	return fmt.Fprintf(stdout, f, args...)
}

func println(args ...interface{}) (int, error) {
	return fmt.Fprintln(stdout, args...)
}

func eprintln(args ...interface{}) (int, error) {
	return fmt.Fprintln(os.Stderr, args...)
}

func eprintf(f string, args ...interface{}) (int, error) {
	return fmt.Fprintf(os.Stderr, f, args...)
}

func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}

func min64(a, b int64) int64 {
	if a < b {
		return a
	}
	return b
}

func max(a, b int) int {
	if a < b {
		return b
	}
	return a
}

func max64(a, b int64) int64 {
	if a < b {
		return b
	}
	return a
}

func abs(a int) int {
	if a < 0 {
		return -a
	}
	return a
}

func abs64(a int64) int64 {
	if a < 0 {
		return -a
	}
	return a
}

func gcd(a, b int) int {
	if b == 0 {
		return a
	}
	return gcd(b, a%b)
}

func gcd64(a, b int64) int64 {
	if b == 0 {
		return a
	}
	return gcd64(b, a%b)
}

// readString() string
// readInt() int
// readInt64() int64
// readFloat64() float64

// -----------------------------------------------------------------------------

func main() {
	defer stdout.Flush()

	for {
		ans, ok := solve()
		if !ok {
			break
		}
		println(ans)
	}

}

func solve() (int, bool) {
	w := readInt()
	h := readInt()
	if w == 0 && h == 0 {
		return 0, false
	}

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

	var ans int
	for i := 1; i-1 < h; i++ {
		for j := 1; j-1 < w; j++ {
			if 0 < c[i][j] {
				ans++
				dfs(c, i, j)
			}
		}
	}
	return ans, true
}

func dfs(c [][]int, y, x int) {
	c[y][x] = 0
	dx := []int{-1, 0, 1, -1, 1, -1, 0, 1}
	dy := []int{-1, -1, -1, 0, 0, 1, 1, 1}
	for i := range dx {
		nx := x + dx[i]
		ny := y + dy[i]
		if 0 < c[ny][nx] {
			dfs(c, ny, nx)
		}
	}
}

// -----------------------------------------------------------------------------

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

using namespace std;

pair<int,int> finish(vector<vector<int>> a,int h,int w){
  for(int i=0;i<h;i++){
    for(int j=0;j<w;j++){
      if(a[i][j]==1){return make_pair(i,j);}
    }
  }
  return make_pair(h,w);
}

//沈めてく
void idlands(int H,int W){
  vector<vector<int>> d(H,vector<int>(W,0));
  queue< pair<int,int> > x;
  for(int i=0;i<H;i++){
    for(int j=0;j<W;j++){
      cin >> d[i][j];
    }
  }
  int l=1;
  int c=0;
  while(finish(d,H,W)!=make_pair(H,W)){
    x.push(finish(d,H,W));
    c+=1;l=x.size();d[x.front().first][x.front().second]=0;
    while(l!=0){
      for(int i=0;i<l;i++){
        int h,w;h=x.front().first;w=x.front().second;
        if(0<h and d[h-1][w]==1){
          x.push(make_pair(h-1,w));d[h-1][w]=0;}
        if(h<H-1 and d[h+1][w]==1){
          x.push(make_pair(h+1,w));d[h+1][w]=0;}
        if(0<w and d[h][w-1]==1){
          x.push(make_pair(h,w-1));d[h][w-1]=0;}
        if(w<W-1 and d[h][w+1]==1){
          x.push(make_pair(h,w+1));d[h][w+1]=0;}
        if(0<h and w<W-1 and d[h-1][w+1]==1){
          x.push(make_pair(h-1,w+1));d[h-1][w+1]=0;}
        if(h<H-1 and 0<w and d[h+1][w-1]==1){
          x.push(make_pair(h+1,w-1));d[h+1][w-1]=0;}
        if(0<h and 0<w and d[h-1][w-1]==1){
          x.push(make_pair(h-1,w-1));d[h-1][w-1]=0;}
        if(h<H-1 and w<W-1 and d[h+1][w+1]==1){
          x.push(make_pair(h+1,w+1));d[h+1][w+1]=0;}
        x.pop();
      }
      l=x.size();
    }
  }
  cout << c << endl;
}

int main(){
  int W,H;
  while(cin >> W >> H and W!=0){
    idlands(H,W);
  }
}

C++: #include<bits/stdc++.h>
using namespace std;
#define fs first
#define sc second
#define pb push_back
#define mp make_pair
#define eb emplace_back
#define ALL(A) A.begin(),A.end()
#define RALL(A) A.rbegin(),A.rend()
typedef long long ll;
typedef pair<ll,ll> P;
const ll mod=1000000007;
const ll LINF=1LL<<60;
const int INF=1<<30;

vector<vector<int>> c(51,vector<int>(51,0));
int w,h;

void search(int x,int y){
	c[x][y] = 0;
	for(int i = -1; i <= 1; i++) {
		for(int j = -1; j <= 1; j++) {
			if (x + i >= 0 && x + i < h && y + j >= 0 && y + j < w && c[x + i][y + j] == 1){
				search(x + i,y + j);
			}
		}
	}
}

int main(){
	while (1) {
		cin>>w>>h;
		if (w == 0 && h == 0){
			break;
		}
		for(int i = 0; i < h; i++) {
			for(int j = 0; j < w; j++) {
				cin >> c[i][j];
			}	
		}
		int ans = 0;

	// for(int i = 0; i < h; i++) {
	// 	for(int j = 0; j < w; j++) {
	// 		cout << c[i][j];
	// 	}
	// 	cout << endl;
	// }
		for(int i = 0; i < h; i++) {
			for(int j = 0; j < w; j++) {
				if (c[i][j] == 1){
					search(i,j);
					ans++;
				}
			}
		}
		cout << ans << endl;
	}
	return 0;
}

C++: 
#include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstdlib>
#include <cmath>
#include <vector>
#include <ctime>
#include <string>
#include <map>
#include <stack>
#include <queue>

using namespace std;

int w, h;
const int MAX = 50;
int c[MAX][MAX];


void check(int x, int y){
	c[x][y] = 0;
    for(int dx = -1; dx <= 1; dx++){
        for(int dy = -1; dy <= 1; dy++){
            if(x + dx >= 0 && x + dx <= h  && y + dy >= 0 && y + dy <= w && c[x + dx][y + dy] == 1){
            	check(x + dx, y + dy);
            } 
        }
    }
	
}

int main(void){

	for(int i = 0; i < MAX ; i++){
		for(int j = 0; j < MAX; j++){
			c[i][j] = 0;
		}
	}


	while((cin >> w) != 0 && (cin >> h) != 0){
		int ans = 0;
		for(int i = 0; i < h ; i++){
			for(int j = 0; j < w; j++){
				cin >> c[i][j];
			}
		}

		for(int i = 0; i < h ; i++){
			for(int j = 0; j < w; j++){
				if(c[i][j] == 1){
					check(i, j);
					ans++;
				}
			}
		}
		cout << ans << endl;
	}
	
    return 0;
}