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<bits/stdc++.h>
using namespace std;
#define OUT(x) cout<<x<<endl
#define DEBUG(x) cout<<#x<<": "<<x
const int BA = 1000;
const int INFTY = (1<<21);
int c[51][51];
int w,h;
int del(int x,int y){
  if(x<0 || y<0 || x>=w || y>= h)return 0;
  if(c[x][y]){
    c[x][y] = 0;
    return del(x+1,y)+del(x,y+1)+del(x+1,y+1)+
      del(x-1,y-1)+del(x-1,y)+del(x,y-1)+del(x+1,y-1)+del(x-1,y+1);
    
  }
  else return 0;
  
}
int solve(int x,int y){
  if(x==0 && y == h)return 0;
  else if(x==w){
    return solve(0,y+1);
  }
  else if(c[x][y]==1){
    del(x,y);
    return solve(x+1,y)+1;
  }
  else return solve(x+1,y);
}
int main(){
  while(cin>>w>>h&&w&&h){
    for(int i=0;i<h;i++){
      for(int j=0;j<w;j++){
	cin >> c[i][j];
      }
    }
    
    cout << solve(0,0) << endl;
  }
}

C++: #include "bits/stdc++.h"

using namespace std;

void dfs(int i, int j, const vector<vector<int> >& c, vector<vector<int> >& arrived, int count) {
    arrived[i][j] = count;

    if (c[i + 1][j] == 1 && arrived[i + 1][j] == 0) {
        dfs(i + 1, j, c, arrived, count);
    }
    if (c[i - 1][j] == 1 && arrived[i - 1][j] == 0) {
        dfs(i - 1, j, c, arrived, count);
    }
    if (c[i][j + 1] == 1 && arrived[i][j + 1] == 0) {
        dfs(i, j + 1, c, arrived, count);
    }
    if (c[i][j - 1] == 1 && arrived[i][j - 1] == 0) {
        dfs(i, j - 1, c, arrived, count);
    }
    if (c[i + 1][j + 1] == 1 && arrived[i + 1][j + 1] == 0) {
        dfs(i + 1, j + 1, c, arrived, count);
    }
    if (c[i + 1][j - 1] == 1 && arrived[i + 1][j - 1] == 0) {
        dfs(i + 1, j - 1, c, arrived, count);
    }
    if (c[i - 1][j + 1] == 1 && arrived[i - 1][j + 1] == 0) {
        dfs(i - 1, j + 1, c, arrived, count);
    }
    if (c[i - 1][j - 1] == 1 && arrived[i - 1][j - 1] == 0) {
        dfs(i - 1, j - 1, c, arrived, count);
    }
}

void Main() {
    while (true) {
        int w, h;
        cin >> w >> h;
        if (w == 0 && h == 0) {
            break;
        }

        vector<vector<int> > c(h + 2, vector<int>(w + 2, 0));
        for (int i = 0; i < h; ++i) {
            for (int j = 0; j < w; ++j) {
                int ct;
                cin >> ct;
                c[i + 1][j + 1] = ct;
            }
        }

        vector<vector<int> > arrived(h + 2, vector<int>(w + 2, 0));
        int count = 0;
        for (int i = 0; i < c.size(); ++i) {
            for (int j = 0; j < c[i].size(); ++j) {
                if (c[i][j] == 1 && arrived[i][j] == 0) {
                    ++count;
                    dfs(i, j, c, arrived, count);
                }
            }
        }

        set<int> ans;
        for (int i = 0; i < c.size(); ++i) {
            for (int j = 0; j < c[i].size(); ++j) {
                if (arrived[i][j] > 0) {
                    ans.insert(arrived[i][j]);
                }
            }
        }
        cout << ans.size() << endl;
    }
}

int main() {
    std::cout << std::fixed << std::setprecision(15);
    Main();
    return 0;
}

C++: #include<iostream>
#include<cstdio>
#include<string>
#include<queue>
#include<stack>
#include<cstdlib>


#define rep(n,cnt) for(int cnt=0;cnt<n;++cnt)

using namespace std;

template <typename TYPE>
void printArray(TYPE* array, int size){
  rep(size,i) cout << array[i] << "\t" << flush;
  cout << endl;
}

int StringToInt(string str){
  return atoi(str.c_str());
}

#define MAX_W 50
#define MAX_H 50

class State{
public:
  int y;
  int x;
  int island_count;
};

int w,h,c[MAX_W][MAX_H];
int count = 0;

void dfs(int sy, int sx){
  c[sy][sx] = 0;

  for(int vy=-1;vy<=1;++vy){
    for(int vx=-1;vx<=1;++vx){
      int y = sy + vy;
      int x = sx + vx;
      if(c[y][x] == 1) dfs(y,x);
    }
  }
}

int main(){
  while(true){
    count = 0;
    cin >> w;
    cin >> h;
    if(w == 0 && h == 0) break;
    rep(h,y){
      rep(w,x){
	cin >> c[y][x];
      }
    }
    
    rep(h,y){
      rep(w,x){
	if(c[y][x] == 1){
	  dfs(y,x);
	  count++;
	}
      }
    }
    cout << count << endl;
  }
}

C++: #include <iostream>
#include <cstring>

using namespace std;


int W, H;
int map[55][55];



void dfs(int cx, int cy) {
	map[cy][cx] = 0;
	
	for (int dx = -1; dx <= 1; dx++) {
		for (int dy = -1; dy <= 1; dy++) {
			if (map[cy + dy][cx + dx] == 1) dfs(cx + dx, cy + dy);
		}
	}
}

int solver() {
	int cnt = 0;
	
	for (int i=0; i<H; i++) {
		for (int j=0; j<W; j++) {
			if (map[i][j] == 1) {
				dfs(j, i);
				cnt++;
			}
		}
	}
	
	return cnt;
}

int main() {
	
	while (1) {
		cin >> W >> H; if (W==0 && H==0) break;
		
		memset(map, 0, sizeof(map));
		for (int i=0; i<H; i++)
			for (int j=0; j<W; j++) cin >> map[i][j];
		
		cout << solver() << endl;
	}
	
	return 0;
}